ACS Publications. Most Trusted. Most Cited. Most Read
Quick View

OR SEARCH CITATIONS

My Activity
Publications
CONTENT TYPES

Figure 1Loading Img
Download Hi-Res ImageDownload to MS-PowerPointCite This:ACS Nano 2021, 15, 3, 4802-4810
RETURN TO ISSUEPREVArticleNEXT

Protected Long-Distance Guiding of Hypersound Underneath a Nanocorrugated Surface

  • Dmytro D. Yaremkevich
    Dmytro D. Yaremkevich
    Experimentelle Physik 2, Technische Universität Dortmund, Otto-Hahn-Str. 4a, 44227 Dortmund, Germany
    More by Dmytro D. Yaremkevich
  • , 
  • Alexey V. Scherbakov*
    Alexey V. Scherbakov
    Experimentelle Physik 2, Technische Universität Dortmund, Otto-Hahn-Str. 4a, 44227 Dortmund, Germany
    Ioffe Institute, Politekhnycheskaya 26, 194021 St. Petersburg, Russia
    *Email: [email protected]
    More by Alexey V. Scherbakov
    Orcidhttp://orcid.org/0000-0001-7358-4164
  • , 
  • Serhii M. Kukhtaruk
    Serhii M. Kukhtaruk
    Experimentelle Physik 2, Technische Universität Dortmund, Otto-Hahn-Str. 4a, 44227 Dortmund, Germany
    Department of Theoretical Physics, V. E. Lashkaryov Institute of Semiconductor Physics, Pr. Nauky 41, 03028 Kyiv, Ukraine
    More by Serhii M. Kukhtaruk
  • , 
  • Tetiana L. Linnik
    Tetiana L. Linnik
    Department of Theoretical Physics, V. E. Lashkaryov Institute of Semiconductor Physics, Pr. Nauky 41, 03028 Kyiv, Ukraine
    More by Tetiana L. Linnik
  • , 
  • Nikolay E. Khokhlov
    Nikolay E. Khokhlov
    Ioffe Institute, Politekhnycheskaya 26, 194021 St. Petersburg, Russia
    More by Nikolay E. Khokhlov
  • , 
  • Felix Godejohann
    Felix Godejohann
    Experimentelle Physik 2, Technische Universität Dortmund, Otto-Hahn-Str. 4a, 44227 Dortmund, Germany
    More by Felix Godejohann
    Orcidhttp://orcid.org/0000-0001-7237-1650
  • , 
  • Olga A. Dyatlova
    Olga A. Dyatlova
    Experimentelle Physik 2, Technische Universität Dortmund, Otto-Hahn-Str. 4a, 44227 Dortmund, Germany
    More by Olga A. Dyatlova
  • , 
  • Achim Nadzeyka
    Achim Nadzeyka
    Raith GmbH, Konrad-Adenauer-Allee 8, 44263 Dortmund, Germany
    More by Achim Nadzeyka
  • , 
  • Debi P. Pattnaik
    Debi P. Pattnaik
    School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
    More by Debi P. Pattnaik
  • , 
  • Mu Wang
    Mu Wang
    School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
    More by Mu Wang
  • , 
  • Syamashree Roy
    Syamashree Roy
    School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
    More by Syamashree Roy
  • , 
  • Richard P. Campion
    Richard P. Campion
    School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
    More by Richard P. Campion
  • , 
  • Andrew W. Rushforth
    Andrew W. Rushforth
    School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
    More by Andrew W. Rushforth
    Orcidhttp://orcid.org/0000-0001-8774-6662
  • , 
  • Vitalyi E. Gusev
    Vitalyi E. Gusev
    LAUM, CNRS UMR 6613, Le Mans Université, 72085 Le Mans, France
    More by Vitalyi E. Gusev
  • , 
  • Andrey V. Akimov
    Andrey V. Akimov
    School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
    More by Andrey V. Akimov
    Orcidhttp://orcid.org/0000-0002-8173-8212
  • , and 
  • Manfred Bayer
    Manfred Bayer
    Experimentelle Physik 2, Technische Universität Dortmund, Otto-Hahn-Str. 4a, 44227 Dortmund, Germany
    Ioffe Institute, Politekhnycheskaya 26, 194021 St. Petersburg, Russia
    More by Manfred Bayer
    Orcidhttp://orcid.org/0000-0002-0893-5949
Cite this: ACS Nano 2021, 15, 3, 4802–4810
Publication Date (Web):February 16, 2021
https://doi.org/10.1021/acsnano.0c09475

Copyright © 2021 The Authors. Published by American Chemical Society. This publication is licensed under

CC-BY-NC-ND 4.0.
  • Open Access

Article Views

1623

Altmetric

-

Citations

3
LEARN ABOUT THESE METRICS
PDF (5 MB)
Get e-Alerts
Supporting Info (3)»
SUBJECTS:

Abstract

High Resolution Image
Download MS PowerPoint Slide

In nanoscale communications, high-frequency surface acoustic waves are becoming effective data carriers and encoders. On-chip communications require acoustic wave propagation along nanocorrugated surfaces which strongly scatter traditional Rayleigh waves. Here, we propose the delivery of information using subsurface acoustic waves with hypersound frequencies of ∼20 GHz, which is a nanoscale analogue of subsurface sound waves in the ocean. A bunch of subsurface hypersound modes are generated by pulsed optical excitation in a multilayer semiconductor structure with a metallic nanograting on top. The guided hypersound modes propagate coherently beneath the nanograting, retaining the surface imprinted information, at a distance of more than 50 μm which essentially exceeds the propagation length of Rayleigh waves. The concept is suitable for interfacing single photon emitters, such as buried quantum dots, carrying coherent spin excitations in magnonic devices and encoding the signals for optical communications at the nanoscale.

This publication is licensed under

CC-BY-NC-ND 4.0.
  • cc licence
  • by licence
  • nc licence
  • nd licence
KEYWORDS:
Acoustic waves with terahertz (THz) and gigahertz (GHz) frequencies, which are often referred to as hypersound, are attractive for applications in quantum computing, sensing, and communications. (1−4) A major advantage is the nanometer wavelength of hypersound which, in contrast to photons, is comparable with the size of single-electron and single-photon devices. Surface acoustic waves (SAWs) of hypersound frequencies, being the high-frequency counterpart of traditional MHz SAWs, have been implemented successfully in quantum technologies as an instrument to control single electron, (5,6) photonic, (7,8) and spintronic (9−11) devices. It has been proposed to use hypersound to connect different nanoobjects (e.g., qubits) on-chip in analogy with wires connecting the elements of traditional electronics. (12−15) For this, the propagation distance of the acoustic signal should be at least comparable with the distance between the source and receiver. SAWs with frequencies up to 50 GHz can propagate on flat surfaces over millimeter distances, (16) but nanodevice architectures on single chips inevitably require nanometer processing and surface corrugation upon which the hypersound diffracts, reducing the SAW’s mean free path from millimeters to micrometers. (17)
In this article, we demonstrate experimentally how subsurface hypersound propagates from the source to the receiver on distances more than 50 μm underneath a nanopatterned metallic layer. The principle is schematically demonstrated in Figure 1a where surface and subsurface waves are propagating along a nanostructured surface. Both waves are generated at point A and serve to deliver the information, for example, a spatially or temporally modulated signal, to point C. Traditional SAWs, that is, Rayleigh-like waves, do not reach the destination due to diffraction and scattering at the nanoobject B located on the SAW’s path. (18) Alternatively, subsurface waves continue to propagate under object B and do not feel any surface corrugation, similar to how a submarine does not feel the storm at the sea surface. This idea is a nanometer analogue for the delivery of acoustic signals using nonattenuating guided underwater sound waves. (19) To realize this concept in practice, the subsurface hypersound should propagate parallel to the surface with preserved coherence and without strong attenuation and leakage to the bulk. Reaching this goal requires the design of structures that support long propagating hypersound modes and the development of methods to generate and detect such modes. In the present work, we achieve both goals. We demonstrate experimentally the propagation of coherent hypersound wavepackets, with a central frequency of ∼20 GHz, on macroscopic distances which essentially exceed the mean free path of high-frequency Rayleigh waves at the corrugated surface.

Figure 1

Figure 1. Experimental setup. (a) Basic concept: Surface waves traveling from A to C are scattered by object B, while subsurface waves freely propagate beneath the corrugated surface. (b) Scheme of the sample. (c) SEM images of the nanograting. (d) Schematic of the experimental setup for measuring phonon propagation with the pump and probe spots separated in space.

High Resolution Image
Download MS PowerPoint Slide

Results and Discussion

ARTICLE SECTIONS
Jump To
The samples consist of lateral one-dimensional nanogratings (NGs) fabricated from metallic (Fe0.81Ga0.19) layers deposited on GaAs substrates. Two samples were studied in our experiment. In the first sample (see Figure 1b), the metallic layer with a thickness of l = 105 nm was deposited onto a GaAs/AlAs superlattice (SL) grown on a (001)-GaAs substrate. As we shall show, the elastic parameters of the SL allow the waveguiding effect for hypersound. In the second sample, the metallic layer with l = 100 nm was deposited directly onto a GaAs substrate without a SL. The NGs with a lateral size of 25 × 100 μm2 consist of grooves of 25 nm depth milled parallel to the [010] crystallographic direction of the GaAs substrate. The grooves and stripes have the same width a, and the corresponding period d in the two gratings has values d = 200 and 150 nm, respectively. The scanning electron microscope image of the NG with d = 200 nm is shown in Figure 1c.
Hypersound waves are excited and detected optically using a picosecond ultrasonic pump–probe technique. (20,21) The schematic of the experiment is shown in Figure 1d. The pump beam from the femtosecond laser is sent in from the side of the GaAs substrate, which is transparent for the laser wavelength 1050 nm, and focused onto the metallic film on a Gaussian spot with radius σ = 1 μm. The probe pulses from another laser with wavelength 780 nm are focused on a spot with a radius of 0.5 μm on the metallic grating. The femtosecond pump pulse induces instantaneously thermal stress in the metallic layer, leading to the generation of the acoustic wavepacket with hypersound frequencies up to 100 GHz. (20) In the presence of the NG, the generated hypersound propagates along the x-direction parallel to the surface and has wavevector components:
(1)
where x is the [100] direction perpendicular to the grooves (see Figure 1b), and qP ≪ 2π/d is the wavevector limited by the size of the pump laser spot (see Methods). The detected reflectivity probe signal ΔR(t) is sensitive to waves with the same qx given by eq 1. In the present experiments, we concentrate on measurements of the probe signals on distances up to 80 μm from the pump spot along the x-axis (x = 0 corresponds to the center of the pump spot, t = 0 corresponds to the time moment when the pump pulse hits the studied structure).
The measured signal ΔR(t) at x = 0, that is, at the point of spatial overlap of the pump and probe spots, in the grating with d = 200 nm and the GaAs/AlAs SL subsurface layer is shown in the upper panel of Figure 2a. The signal shows high-frequency oscillations sitting on a slowly varying background. The origin of the oscillations is elastic vibrations, that is, coherent hypersound waves, while the slow background, shown by the red solid line, is known to be due to the modulation of the refractive index by hot electrons, thermal phonons, and low-frequency acoustic motion of the surface excited by the optical pump pulse. (20,21) The inset in Figure 2a shows the fast Fourier transform (FFT) of the measured signal within three spectral bands: B1 (10–15 GHz), B2 (15–20 GHz), and B3 (25–30 GHz). The low-frequency band B1 includes an intense narrow spectral line at fR1 = 12.1 GHz which corresponds to the first-order Rayleigh-like mode observed earlier in experiments with NGs. (22−26) The other spectral bands include several surface modes, quasi-surface (skimming) modes, and bulk modes, which are commonly seen in experiments with gratings when the pump and probe pulses overlap. (17,25,26) The lower panel shows the temporal signals after filtering in the different spectral bands. The signal in B1 has the longest lifetime, while the oscillations in the bands B2 and B3 decay much more quickly.

Figure 2

Figure 2. Experimental signals. (a) Upper panel: Signal detected when the pump and probe spots overlap in space; the inset is the FFT of the temporal signal. Lower panel: Temporal traces after filtering of the measured signal from the upper panel in three frequency bands marked in the inset. (b) Same as (a) but measured when the pump and probe spots are separated on the surface by 10 μm.

High Resolution Image
Download MS PowerPoint Slide
Figure 2b shows the results for ΔR(t) measured when the pump and probe spots are separated in space by 10 μm along the x-direction. In this case, only hypersound waves propagating along the surface perpendicular to the grooves are detected. From the raw signal (Figure 2a), it is seen that the slowly varying background is absent, which is explained by localization of thermal phonons and hot electrons inside the pump spot. The measured signals ΔR(t) show oscillations that sit on a background from the pulse with a duration of ∼1 ns (shown by the solid red line). This nanosecond pulse corresponds to the generated acoustic signal with qx ≤ qP (n = 0), (27) which is excited also in a plain film without NG, and will not be discussed further. The filtered signals (lower panel) and their FFTs (inset) differ significantly from the case x = 0: There are several hypersound modes in B1, and the spectral line in B2 centered at fW ∼ 17 GHz has an intensity comparable with the modes in B1. There is a weak contribution from high-frequency modes in B3. The signals in the different spectral bands appear at different delay times ti ≤ x/si (si is the group velocity of the wavepacket in the corresponding frequency band) relative to the pump pulse, which suggests different velocities si of the corresponding hypersound modes. All reflectivity traces show beatings in the filtered signals which point toward multiple mode composition of the hypersound waves in each spectral band.
Figure 3a shows the evolution of the FFTs with the increase of the distance to x = 50 μm. The normalized spectra show that only the hypersound modes in B2 with frequencies fW ∼ 17 GHz remain in the wavepacket at large distances. We shall call these long propagating modes waveguide modes (W-modes). The reason for this name will become clear after identifying their polarization and spatial distribution. All other modes, including the traditional Rayleigh-like modes in the B1 spectral band (further referred to as R-modes), decay much faster. Figure 3b compares the decays of the R- and W- modes with distance. Blue circles show the dependence of the spectral amplitude of the first-order Rayleigh mode (R1) at fR1 = 12.1 GHz. This mode dominates in the signal measured at x = 0 and demonstrates the longest propagation among the R-modes. The mean free path for the R1-mode is l̅R1 = 7.2 μm, so that it is hardly observable at x = 30 μm. In contrast, the W-modes have a much larger mean free path l̅W. The distance dependence of their mean spectral amplitude averaged over the B2 frequency band, shown by red squares, demonstrates a nonmonotonic decay and is almost constant at x > 30 μm. The W-modes are uniquely detected in the time domain at x = 50 μm and larger (our measurements are limited by the NG length). Figure 3c shows the filtered signals for the W-modes (B2 spectral band) at several distances from the pump spot. The signals possess beatings, and their exact shape depends on x. This indicates that the signal in this spectral band consists of several hypersound modes propagating at different velocities. The inset in Figure 3c shows the linear dependence of the arrival time of the W-modes (determined from the center of the respective wavepackets) on the coordinate x. From this dependence, we obtain the mean sound velocity s̅W = 3170 m/s, which is slower than the sound velocities for transverse (TA) sound in the [100] direction in metallic (Fe,Ga) (sFeGa = 3955 m/s) and GaAs (sGaAs = 3346 m/s), but is essentially faster than the measured speed of sound for the R1-mode in the studied sample (sR1 = 1950 m/s).

Figure 3

Figure 3. Dependence on the distance between source and detector. (a) FFTs obtained from the signals measured at various distances x between the pump and probe spots. Each spectrum is normalized to its maximum spectral amplitude. (b) Dependences of the spectral amplitude of the filtered signals for the Rayleigh wave (R1 mode) and the mean spectral density for the waveguide modes (W-modes) on the distance between the pump and probe spots. Solid lines show the fits of the experimental data by an exponential decay, which serve to estimate the averaged mean free path for the propagating modes. The data and fit curves are normalized for clear presentation. (c) Temporal signals after filtering in the frequency band B2 for various distances between the pump and probe spots; the inset shows the dependence of the arrival time of the bunch around 17 GHz on the distance.

High Resolution Image
Download MS PowerPoint Slide
Another nanograting with d = 150 nm deposited on the GaAs/AlAs SL sublayer shows similar results, but metallic layers deposited onto a GaAs substrate without SL do not show any modes, which propagate on distances larger than 10 μm in any spectral band. The experimental results and the calculated values of sound group velocities si, estimated mean free paths l̅i, and maximum distances limax, at which hypersound is clearly seen in the FFTs above the noise level, are presented in the Supporting Information for all measured samples. Thus, we conclude that the SL subsurface layer is essential to observe hypersound modes propagating on long distances.
To understand the difference in the propagation length for Rayleigh-like and W- hypersound modes, we identify the origins of the observed spectral lines in the FFTs in the phonon dispersion curves. Figure 4a shows these dispersion curves, f(kx), for the sample with the d = 200 nm nanograting in the metallic Fe0.81Ga0.19 layer, deposited on the GaAs/AlAs SL. Here kx is the Bloch wavevector and qx = kx + n2π/d. Only modes with atom displacements u (x, z) in the sagittal plane (xz-plane in Figure 1b) are considered. The dispersion curves are shown in the range near the center of the folded Brillouin zone for the frequency range around n = 1. The calculated dispersions for the plain structure without NG (see Section S2 in Supporting Information) help us to identify the origins of the modes. We attribute the dispersion branches R1 and R1* to the lowest first-order Rayleigh-like mode. In the periodic structure with NG, this mode is split into the symmetric (R1) and antisymmetric (R1*) modes with even and odd distributions of the z-component of the displacement relative to the center of the NG groove, with a spectral gap at kx = 0. The spatial distributions of these modes are concentrated in the metallic layer, as demonstrated in Figure 4b. Both R1 and R1* modes are observed in the experiments for relatively small distances 2 < x < 15 μm at fR1 = 12.1 GHz and fR1* = 11.2 GHz, respectively (for example, see the inset in Figure 2b). The modes R2 and R2* are the second-order Rayleigh-like modes, often called Sezawa-like modes. (28) Similar to the R1-modes, these modes are concentrated in the (Fe,Ga) layer. The excellent agreement with the calculated frequencies fi and sound velocities si allows us to identify unambiguously the symmetric (R1 and R2) and antisymmetric (R1* and R2*) propagating Rayleigh modes in the experimental spectra.

Figure 4

Figure 4. Dispersions and spatial distributions of the hypersound modes. (a) Calculated dispersion curves for hypersound modes propagating along the surface in the structure with the Fe0.81Ga0.19 nanograting with d = 200 nm deposited on the GaAs/AlAs SL. (b) Spatial distribution of the absolute value of displacement vector (exaggerated for clarity) for the Rayleigh waves (R1 and R1*) localized in the metallic layer with the nanograting and for five waveguiding (W) phonon modes localized in the GaAs/AlAs SL.

High Resolution Image
Download MS PowerPoint Slide
The most important result revealed by the dispersion curves is the existence of the W-modes with linear dispersion branches that are degenerate at kx = 0 and fW ∼ 17 GHz, that is, with Dirac cone-type dispersions. The striking difference between the W- and R-modes is their spatial distribution, as shown in Figure 4b. While the R-modes are concentrated in the metallic layer, the W-modes are localized in the sublayer with the GaAs/AlAs SL, well below the NG. The W-modes have an analogy with the Lamb modes in plates and behave as waveguide modes. In total, there are 11 pairs of W-modes localized in the SL (see Section S3 in Supporting Information for details). Their frequencies and group velocities cover the ranges fW = 16.5–18 GHz and sW = 2800–3600 m/s, respectively. The excellent agreement between calculated and measured frequencies and their velocities leads us to the conclusion that the waveguide W-modes are those with the long propagation lengths in our samples.
The dispersion curves and spatial distributions for the sample without a SL subsurface layer show that R-modes exist there with dispersion relations very similar to the considered case with a SL, but W-modes are not present. This theoretical result confirms that the observation of W-modes is governed exclusively by the presence of the GaAs/AlAs SL which acts as a multichannel waveguide. The same conclusion can be drawn by comparing the signals measured on the samples with and without a SL sublayer.
The exciting property of the W-modes is their ability to propagate parallel to the surface for long distances. This is explained by the localization of the W-modes in the SL layer as shown in Figure 4b. The (Fe,Ga)/SL and SL/GaAs interfaces play the role of confining borders for Lamb-like modes (29) in the SL sublayer. The structure could be viewed as a waveguiding plate loaded on top by a layer of finite thickness and at the bottom by the infinite substrate. In comparison with a Lamb plate in air or water, the structure is asymmetric both geometrically and in terms of the loading materials. In contrast to Rayleigh waves at a plain surface, the corrugation results in the leakage of both R- and W-modes to the bulk. (18) However, the calculations show that the losses into the bulk modes are much smaller for the guided W-modes than for the R-modes. The calculated quality factor, Q, reaches ∼105 for the W-modes, but does not exceed ∼103 for the R-modes (see Table S2 in the Supporting Information). This difference is explicitly demonstrated in the Supporting Video 1, which animates the calculated propagation of the excited hypersound in the studied sample and visualizes the emissions from R-modes and W-modes into bulk waves. When the R-modes and W-modes are sufficiently spatially separated to distinguish these two emissions in the animation (after 4.5 ns delay from the optical excitation), the strong leakage of R-modes to the bulk is clearly observed, while the weak leakage of W-modes is hardly visible. The linear dispersion of W-modes (see Figure 4a), in addition to their high Q factors, also indicates that the grating, which causes the excitation of the hypersound waveguide modes, has a small influence on their propagation. Thus, the much larger broadening of the R-modes’ wavepacket in comparison with the wavepacket of the W-modes is clearly visible already at small x (compare the filtered signals for the B1 and B2 bands in Figure 2b).
The waveguiding observed experimentally is a multimodal effect. The bunch of propagating W-modes covers the frequency range from 16 to 18 GHz (see the FFTs in Figure 3a). The temporal signals and their FFTs allow us to distinguish several modes propagating with different velocities. As a result, we observe temporal beatings in the signals presented in Figure 3c and a nonmonotonic dependence of the mean spectral density on the coordinate x in Figure 3b. To illustrate the multimodal character of the waveguiding effect, we present a simulation of the transient reflectivity signal induced by a propagating multimode wavepacket in the Supporting Video 2. Two signals from this simulation are presented together with the experimental signals for x = 20 and 40 μm in Figure 5. In the simulations, we did not aim for a perfect agreement with the experiment and limited the signal in the B2 band to the sum of four W-modes that are simultaneously excited at the excitation spot with the same amplitudes, spatial distributions, and initial phases. Their frequencies fw= 16.532, 17.026, 17.223, and 17.455 GHz and corresponding velocities sw= 3266, 3310, 3591, and 2881 m/s are taken from the calculated dispersion curves in Figure 4a and correspond to kx = 0.01π/d. It is seen that the arrival time of the hypersound bunch and its temporal width are in good agreement with the experiment. The simulated spatial-temporal evolution of the signal shows also pronounced beatings, which agrees with the experimental observations and supports the conclusion about the multimodal character of the waveguiding effect.

Figure 5

Figure 5. W-mode wavepackets. Measured (red) and simulated (black) phonon wavepackets in the B2 spectral band for two propagation distances: x = 20 μm (a) and 40 μm (b). In the simulations, four W-modes with frequencies fw = 16.532, 17.026, 17.223, and 17.455 GHz and velocities sw = 3266, 3310, 3591, and 2881 m/s are summed.

High Resolution Image
Download MS PowerPoint Slide

Conclusions

ARTICLE SECTIONS
Jump To
In summary, we have realized experimentally the generation and detection of acoustic waves with a frequency up to 20 GHz, which propagate underneath a corrugated surface. These hypersonic waves propagate on a distance of more than 50 μm and lose their energy to bulk phonons much less efficiently than Rayleigh waves, which propagate only on several micrometers due to scattering on the nanostructured surfaces.
For prospective applications in communications, it is important that the subsurface W-modes faithfully carry the surface morphology imprinted at the point of excitation, which must then be read-out at the point of detection. In the particular case described in the present experiments, the morphology is carried by the generated and detected hypersound wavevector qx ≈ 2π/d, defined by the NG period. In the general case, the excitation and detection points could include nanophononic cavities (30) coupled with the subsurface waveguide. A further advantage over traditional Rayleigh-like modes may be taken from the bunched character of the subsurface W-modes, the number of which is controlled by the width of the waveguiding layer. This makes possible using the same subsurface waveguide for encoding information at different acoustic frequencies with the same qx by resonant driving. (31)
The possibility to deliver information by hypersound well beneath corrugated surfaces on macroscopic distances has a direct perspective to control a single photon emission from buried quantum nanoobjects, (8,32,33) which quantum efficiency decreases strongly when located near the surface. Subsurface hypersound may be used to control the emission from a Bose condensate in polariton microcavities located at a micrometer distance from the surface. (34) The technique may be applied to control exciton resonances in two-dimensional van der Waals nanolayers, which require passivation for high quantum efficiency. (35,36) The (Fe,Ga) metallic layer used in our experiment is a ferromagnet, known as Galfenol. (37) It possesses a strong magnon–phonon coupling which allows the conversion of magnon excitations to hypersound and vice versa. (38) In magnonic devices, the described concept of a nanostructured ferromagnetic layer deposited on a hypersound waveguide can be used for transmitting coherent spin excitations. (39,40) The preliminary measurements show that despite the dominating localization of the W-modes in the SL, their tail located in the Galfenol layer has a sufficiently large amplitude for carrying coherent magnons of the corresponding frequencies for distances exceeding 50 μm. This effect, however, is out of the scope of the present paper and will be addressed elsewhere.
It is appealing to excite the guided subsurface modes electrically without using bulky ultrafast lasers. This method, however, should be different from standard techniques for generating SAWs with interdigital transducers. It is necessary to excite a bulk hypersonic wave, which propagates perpendicular to the surface and carries the information encoded at the surface (e.g. by a grating) in terms of its lateral amplitude and phase modulation. When incident on the undersurface waveguide, this laterally modulated wave transfers the encoded information to the W-modes. The electrical generation of bulk hypersonic waves at frequencies higher than 10 GHz is challenging. Recently such generation of hypersound with frequency up to 20 GHz has been demonstrated with piezoelectric ZnO transducers; (41) application of such an electrical technique to the corrugated surface could lead to wider applications of subsurface hypersound.

Methods

ARTICLE SECTIONS
Jump To

Sample Production

The studied samples were epitaxially grown on commercial GaAs substrates [(100)-semi-insulating GaAs]. The SL was produced by molecular beam epitaxy, and the Fe0.81Ga0.19 layers were deposited by magnetron sputtering. The nanogratings were fabricated through focused ion beam milling (Raith VELION) with both 100 and 75 nm lines and spaces over an area of 25 μm × 100 μm. To ensure high beam resolution during the patterning of the gratings, a low Ga+ beam current of 22 pA was applied at 35 keV beam energy. The milling dose was set to 0.3 nC/μm2, resulting in the groove depth of 25 nm.

Time-Resolved Pump–Probe Measurements

The pump–probe scheme was realized using two mode-locked erbium-doped ring fiber lasers (TOPTICA FemtoFiber Ultra 1050 and FemtoFiber Ultra 780). The lasers generate pulses of 150 fs duration with a repetition rate of 80 MHz at wavelengths of 1050 nm (pump pulses) and 780 nm (probe pulses). The pump beam was focused by a microscope objective (20×; NA = 0.4) to the backside of the metal layer through the GaAs substrate and GaAs/AlAs SL, which are transparent for the pump wavelength. The focused pump spot had a Gaussian intensity distribution , where r is the distance from the center of the spot and σ = 1 μm is the spot radius at 1/√e level. The maximal used pulsed excitation density was 8 mJ/cm2. The probe beam was focused by another microscope objective (100×; NA = 0.8) to the front side of the sample. The focused probe spot had a Gaussian distribution also with σ = 0.5 μm and an energy density of 2 mJ/cm2. The temporal resolution was achieved employing an asynchronous optical sampling technique. (42) The pump and probe oscillators were locked with a frequency offset of 1600 Hz. In combination with the 80 MHz repetition rate, it allowed measurement of the time-resolved signals in a time window of 12.5 ns with a time resolution of <1 ps. The distance between the centers of the pump and probe spots was controlled with a precision of 0.05 μm. Two-dimensional spatial scanning across the nanograting surface confirmed the directional propagation of the hypersound wavepackets along the reciprocal lattice vector of the nanograting. At the considered propagation distances, the influence of diffraction on these acoustic beams is negligible and cannot be observed. The measured size of the hypersound beams and the y-distribution of the modes’ amplitudes correspond to the size of the pump spot at the point of excitation. Only the low-frequency background Rayleigh wave [see the filtered (<5 GHz) signal in Figure 2b] is emitted in all surface directions and exhibits cylindrical symmetry.

Transformation of Optically Generated Stress to Hypersound

The guided modes of interest belong to the system of acoustic eigenmodes of the sample, which are all spatially periodic because of the periodicity imposed by the nanograting (Floquet–Bloch theorem). Each eigenmode contains an infinite number of wavevectors: qx = kx + n(2π/d), where kx is the Bloch vector, d is the NG period, and n is an integer, but one spatial harmonic with a certain n dominates. A particular acoustic eigenmode is excited with nonzero amplitude when the frequency spectrum of the photoinduced stress contains the frequency of the eigenmode and the lateral distribution of the stress contains the wavevector of this mode. (22) The intensity envelope of the fs laser pulses applied in our experiments contains frequencies up to ∼0.1 THz and, thus, covers the frequencies of the considered guided modes. In contrast, the spatial spectrum of the stress that is induced by the pump light focused on the interface of the SL and metallic layer (opposite to the open surface with the NG) is limited by the spatial pump intensity distribution. For a Gaussian distribution of the laser intensity along the x-axis , the spectrum of the wavevectors, qP, generated by the photoexcited stress is proportional to . Due to the large size of the laser spot in comparison with the NG period, this spectrum does not contain components of qx with nonzero n. However, the generation of all acoustic eigenmodes is possible due to the matching of the photoinduced stress and the n = 0 components of these eigenmodes.

Calculation of Hypersound Dispersion and Spatial Distribution of Phonon Modes

We use COMSOL Multiphysics for calculation of the phonon dispersion in our system. For this, we consider a NG unit cell and apply Floquet–Bloch periodic boundary conditions, that is, ud = usexp(−ikxd), where ud and us are the atom displacements at the destination and source boundaries, respectively, and kx is a Bloch wavenumber. At the open NG surface, we use free boundary conditions. For the simulation of the semi-infinite substrate, we use a perfectly matched layer (PML) at the backside of the substrate. The stiffness tensor components, Ckl, and the mass density, ρ, used for the calculations are for Fe0.81Ga0.19 (ref (32)): C11 = 209 GPa, C12 = 156 GPa, C44 = 122 GPa, ρ = 7800 kg/m3; for GaAs C11 = 119 GPa, C12 = 53.8 GPa, C44 = 59.5 GPa, ρ = 5316 kg/m3; for AlAs C11 = 119.9 GPa, C12 = 57.5 GPa, C44 = 56.6 GPa, ρ = 3760 kg/m3. The dispersion and modes’ spatial distributions are obtained by an eigenfrequency analysis. Most of the solutions are shown in Figure 4a. There are also solutions arising due to the finite size of the simulated substrate, but they are not related to the experimentally observed effects and are, thus, ignored. To select the modes localized in the NG and SL, we used the approach described elsewhere. (43) We characterize the localization degree with the quality factor Q and parameter p defined by
(2)
where Fe is the elastic free energy density and the averaging is performed over two areas: The L-area includes the Fe0.81Ga0.19 film and the SL, and the S-area corresponds to the PML. Only W-modes with p ≫ 1 propagate for a long distance. The value of p depends on qx. The calculations show that for the Fe0.81Ga0.19 film p > 100 and Q > 5 × 103 for 4 W-modes at qx ≈ 2π/d (see Section S3 in Supporting Information). These four W-modes from the total of 11 pairs are considered as the best candidates for long propagating subsurface modes in our experiments. The existence of the W-modes with long propagation length is confirmed by a semianalytical consideration which is described in Supporting Information (Section S2).

Supporting Information

ARTICLE SECTIONS
Jump To

The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsnano.0c09475.

  • Experimental and theoretical data for all the studied samples; elastic equations and their semi-analytical solutions for an unpatterned metallic film on a GaAs substrate and on a SL; spatial distributions and main parameters of the W-modes for the grating with 200 nm period (PDF)

  • Video 1: Spatial-temporal modeling (COMSOL Multiphysics) of the hypersound propagation in the structure with a GaAs/AlAs SL and a Fe0.81Ga0.19 nanograting with period d = 200 nm after excitation by the pump pulse. The color map illustrates the time derivative of the z-component of the displacement vector. The black horizontal lines show the boundaries between the different materials of the structure (MOV)

  • Video 2: Temporal evolution of the guided wavepacket consisting of four W-modes with frequencies fw= 16.532, 17.026, 17.223, and 17.455 GHz and corresponding velocities sw= 3266, 3310, 3591, and 2881 m/s, taken from the calculated dispersions. The modes are simultaneously excited at the excitation spot with the same amplitudes, spatial distributions, and initial phases (MOV)

Terms & Conditions

Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.

Author Information

ARTICLE SECTIONS
Jump To
  • Corresponding Author
  • Authors
    • Dmytro D. Yaremkevich - Experimentelle Physik 2, Technische Universität Dortmund, Otto-Hahn-Str. 4a, 44227 Dortmund, Germany
    • Serhii M. Kukhtaruk - Experimentelle Physik 2, Technische Universität Dortmund, Otto-Hahn-Str. 4a, 44227 Dortmund, Germany;  Department of Theoretical Physics, V. E. Lashkaryov Institute of Semiconductor Physics, Pr. Nauky 41, 03028 Kyiv, Ukraine
    • Tetiana L. Linnik - Department of Theoretical Physics, V. E. Lashkaryov Institute of Semiconductor Physics, Pr. Nauky 41, 03028 Kyiv, Ukraine
    • Nikolay E. Khokhlov - Ioffe Institute, Politekhnycheskaya 26, 194021 St. Petersburg, Russia
    • Felix Godejohann - Experimentelle Physik 2, Technische Universität Dortmund, Otto-Hahn-Str. 4a, 44227 Dortmund, Germany;  Orcidhttp://orcid.org/0000-0001-7237-1650
    • Olga A. Dyatlova - Experimentelle Physik 2, Technische Universität Dortmund, Otto-Hahn-Str. 4a, 44227 Dortmund, Germany
    • Achim Nadzeyka - Raith GmbH, Konrad-Adenauer-Allee 8, 44263 Dortmund, Germany
    • Debi P. Pattnaik - School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
    • Mu Wang - School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
    • Syamashree Roy - School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
    • Richard P. Campion - School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
    • Andrew W. Rushforth - School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom;  Orcidhttp://orcid.org/0000-0001-8774-6662
    • Vitalyi E. Gusev - LAUM, CNRS UMR 6613, Le Mans Université, 72085 Le Mans, France
    • Andrey V. Akimov - School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom;  Orcidhttp://orcid.org/0000-0002-8173-8212
    • Manfred Bayer - Experimentelle Physik 2, Technische Universität Dortmund, Otto-Hahn-Str. 4a, 44227 Dortmund, Germany;  Ioffe Institute, Politekhnycheskaya 26, 194021 St. Petersburg, Russia;  Orcidhttp://orcid.org/0000-0002-0893-5949
  • Notes
    The authors declare no competing financial interest.

Acknowledgments

ARTICLE SECTIONS
Jump To

The work was supported by the Bundesministerium fur Bildung und Forschung through the project VIP+ “Nanomagnetron” and by the Deutsche Forschungsgemeinschaft in the frame of the Collaborative Research Center TRR 142 (project A06 “Tailored ultrafast acoustics for light emission modulation”). The cooperation between TU Dortmund, the Lashkaryov Institute, and the Ioffe Institute was supported by the Volkswagen Foundation (grant no. 97758).

References

ARTICLE SECTIONS
Jump To

This article references 43 other publications.

  1. 1
    Satzinger, K. J.; Zhong, Y. P.; Chang, H.-S.; Peairs, G. A.; Bienfait, A.; Chou, M.-H.; Cleland, A. Y.; Conner, C. R.; Dumur, É.; Grebel, J.; Gutierrez, I.; November, B. H.; Povey, R. G.; Whiteley, S. J.; Awschalom, D. D.; Schuster, D. I.; Cleland, A. N. Quantum Control of Surface Acoustic-Wave Phonons. Nature 2018, 563, 661– 665,  DOI: 10.1038/s41586-018-0719-5
    Google Scholar
    1
    Quantum control of surface acoustic-wave phonons
    Satzinger, K. J.; Zhong, Y. P.; Chang, H.-S.; Peairs, G. A.; Bienfait, A.; Chou, Ming-Han; Cleland, A. Y.; Conner, C. R.; Dumur, E.; Grebel, J.; Gutierrez, I.; November, B. H.; Povey, R. G.; Whiteley, S. J.; Awschalom, D. D.; Schuster, D. I.; Cleland, A. N.
    Nature (London, United Kingdom) (2018), 563 (7733), 661-665CODEN: NATUAS; ISSN:0028-0836. (Nature Research)
    One of the hallmarks of quantum physics is the generation of non-classical quantum states and superpositions, which has been demonstrated in several quantum systems, including ions, solid-state qubits and photons. However, only indirect demonstrations of non-classical states have been achieved in mech. systems, despite the scientific appeal and tech. utility of such a capability1,2, including in quantum sensing, computation and communication applications. This is due in part to the highly linear response of most mech. systems, which makes quantum operations difficult, as well as their characteristically low frequencies, which hinder access to the quantum ground state3-7. Here we demonstrate full quantum control of the mech. state of a macroscale mech. resonator. We strongly couple a surface acoustic-wave8 resonator to a superconducting qubit, using the qubit to control and measure quantum states in the mech. resonator. We generate a non-classical superposition of the zero- and one-phonon Fock states and map this and other states using Wigner tomog.9-14. Such precise, programmable quantum control is essential to a range of applications of surface acoustic waves in the quantum limit, including the coupling of disparate quantum systems15,16.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXitlGgurzJ&md5=edd5f9d8ce869736f6569f0b5572ad85
  2. 2
    Delsing, P.; Cleland, A. N.; Schuetz, M. J. A.; Knörzer, J.; Giedke, G.; Cirac, J. I.; Srinivasan, K.; Wu, M.; Balram, K. C.; Bäuerle, C.; Meunier, T.; Ford, C. J. B.; Santos, P. V.; Cerda-Méndez, E.; Wang, H.; Krenner, H. J.; Nysten, E. D. S.; Weiß, M.; Nash, G. R.; Thevenard, L. The 2019 Surface Acoustic Waves Roadmap. J. Phys. D: Appl. Phys. 2019, 52, 353001,  DOI: 10.1088/1361-6463/ab1b04
    Google Scholar
    2
    The 2019 surface acoustic waves roadmap
    Delsing, Per; Cleland, Andrew N.; Schuetz, Martin J. A.; Knoerzer, Johannes; Giedke, Geza; Cirac, J. Ignacio; Srinivasan, Kartik; Wu, Marcelo; Balram, Krishna Coimbatore; Baeuerle, Christopher; Meunier, Tristan; Ford, Christopher J. B.; Santos, Paulo V.; Cerda-Mendez, Edgar; Wang, Hailin; Krenner, Hubert J.; Nysten, Emeline D. S.; Weiss, Matthias; Nash, Geoff R.; Thevenard, Laura; Gourdon, Catherine; Rovillain, Pauline; Marangolo, Max; Duquesne, Jean-Yves; Fischerauer, Gerhard; Ruile, Werner; Reiner, Alexander; Paschke, Ben; Denysenko, Dmytro; Volkmer, Dirk; Wixforth, Achim; Bruus, Henrik; Wiklund, Martin; Reboud, Julien; Cooper, Jonathan M.; Fu, YongQing; Brugger, Manuel S.; Rehfeldt, Florian; Westerhausen, Christoph
    Journal of Physics D: Applied Physics (2019), 52 (35), 353001CODEN: JPAPBE; ISSN:0022-3727. (IOP Publishing Ltd.)
    A review. Today, surface acoustic waves (SAWs) and bulk acoustic waves are already two of the very few phononic technologies of industrial relevance and can been found in a myriad of devices employing these nanoscale earthquakes on a chip. Acoustic radio frequency filters, for instance, are integral parts of wireless devices. SAWs in particular find applications in life sciences and microfluidics for sensing and mixing of tiny amts. of liqs. In addn. to this continuously growing no. of applications, SAWs are ideally suited to probe and control elementary excitations in condensed matter at the limit of single quantum excitations. Even collective excitations, classical or quantum are nowadays coherently interfaced by SAWs. This wide, highly diverse, interdisciplinary and continuously expanding spectrum literally unites advanced sensing and manipulation applications. Remarkably, SAW technol. is inherently multiscale and spans from single at. or nanoscopic units up even to the millimeter scale. The aim of this Roadmap is to present a snapshot of the present state of surface acoustic wave science and technol. in 2019 and provide an opinion on the challenges and opportunities that the future holds from a group of renown experts, covering the interdisciplinary key areas, ranging from fundamental quantum effects to practical applications of acoustic devices in life science.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhvVOrtrvO&md5=5cb98dbb5dc28af81ed817b8369c502d
  3. 3
    Hann, C. T.; Zou, C.-L.; Zhang, Y.; Chu, Y.; Schoelkopf, R. J.; Girvin, S. M.; Jiang, L. Hardware-Efficient Quantum Random Access Memory with Hybrid Quantum Acoustic Systems. Phys. Rev. Lett. 2019, 123, 250501,  DOI: 10.1103/PhysRevLett.123.250501
    Google Scholar
    3
    Hardware-Efficient Quantum Random Access Memory with Hybrid Quantum Acoustic Systems
    Hann, Connor T.; Zou, Chang-Ling; Zhang, Yaxing; Chu, Yiwen; Schoelkopf, Robert J.; Girvin, S. M.; Jiang, Liang
    Physical Review Letters (2019), 123 (25), 250501CODEN: PRLTAO; ISSN:1079-7114. (American Physical Society)
    Hybrid quantum systems in which acoustic resonators couple to superconducting qubits are promising quantum information platforms. High quality factors and small mode vols. make acoustic modes ideal quantum memories, while the qubit-phonon coupling enables the initialization and manipulation of quantum states. We present a scheme for quantum computing with multimode quantum acoustic systems, and based on this scheme, propose a hardware-efficient implementation of a quantum random access memory (QRAM). Quantum information is stored in high-Q phonon modes, and couplings between modes are engineered by applying off-resonant drives to a transmon qubit. In comparison to existing proposals that involve directly exciting the qubit, this scheme can offer a substantial improvement in gate fidelity for long-lived acoustic modes. We show how these engineered phonon-phonon couplings can be used to access data in superposition according to the state of designated address modes-implementing a QRAM on a single chip.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXjtFOitrc%253D&md5=1bdc7974ce70af9dd3e9b12b562afcd7
  4. 4
    Clerk, A. A.; Lehnert, K. W.; Bertet, P.; Petta, J. R.; Nakamura, Y. Hybrid Quantum Systems with Circuit Quantum Electrodynamics. Nat. Phys. 2020, 16, 257– 267,  DOI: 10.1038/s41567-020-0797-9
    Google Scholar
    4
    Hybrid quantum systems with circuit quantum electrodynamics
    Clerk, A. A.; Lehnert, K. W.; Bertet, P.; Petta, J. R.; Nakamura, Y.
    Nature Physics (2020), 16 (3), 257-267CODEN: NPAHAX; ISSN:1745-2473. (Nature Research)
    Abstr.: The rise of quantum information science has provided new perspectives on quantum mechanics, as well as a common language for quantum engineering. The focus on platforms for the manipulation and processing of quantum information bridges between different research areas in physics as well as other disciplines. Such a crossover between borders is well embodied by the development of hybrid quantum systems, where heterogeneous phys. systems are combined to leverage their individual strengths for the implementation of novel functionalities. In the microwave domain, the hybridization of various quantum degrees of freedom has been tremendously helped by superconducting quantum circuits, owing to their large zero-point field fluctuations, small dissipation, strong nonlinearity and design flexibility. These efforts take place by expanding the framework of circuit quantum electrodynamics. Here, we review recent research on the creation of hybrid quantum systems based on circuit quantum electrodynamics, encompassing mech. oscillators, quantum acoustodynamics with surface acoustic waves, quantum magnonics and coupling between superconducting circuits and ensembles or single spins.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXktFelsbw%253D&md5=4ff218a5de90caf4134466622c8ea0e4
  5. 5
    Bertrand, B.; Hermelin, S.; Takada, S.; Yamamoto, M.; Tarucha, S.; Ludwig, A.; Wieck, A. D.; Bäuerle, C.; Meunier, T. Fast Spin Information Transfer Between Distant Quantum Dots Using Individual Electrons. Nat. Nanotechnol. 2016, 11, 672– 676,  DOI: 10.1038/nnano.2016.82
    Google Scholar
    5
    Fast spin information transfer between distant quantum dots using individual electrons
    Bertrand, B.; Hermelin, S.; Takada, S.; Yamamoto, M.; Tarucha, S.; Ludwig, A.; Wieck, A. D.; Bauerle, C.; Meunier, T.
    Nature Nanotechnology (2016), 11 (8), 672-676CODEN: NNAABX; ISSN:1748-3387. (Nature Publishing Group)
    Transporting ensembles of electrons over long distances without losing their spin polarization is an important benchmark for spintronic devices. It usually requires injecting and probing spin-polarized electrons in conduction channels using ferromagnetic contacts or optical excitation. In parallel with this development, important efforts have been dedicated to achieving control of nanocircuits at the single-electron level. The detection and coherent manipulation of the spin of a single electron trapped in a quantum dot are now well established. Combined with the recently demonstrated control of the displacement of individual electrons between two distant quantum dots, these achievements allow the possibility of realizing spintronic protocols at the single-electron level. Here, we demonstrate that spin information carried by one or two electrons can be transferred between two quantum dots sepd. by a distance of 4 μm with a classical fidelity of 65%. We show that at present it is limited by spin flips occurring during the transfer procedure before and after electron displacement. Being able to encode and control information in the spin degree of freedom of a single electron while it is being transferred over distances of a few micrometres on nanosecond timescales will pave the way towards 'quantum spintronics' devices, which could be used to implement large-scale spin-based quantum information processing.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XptVSrs7w%253D&md5=0292b4872388af475677e39691d80d20
  6. 6
    Takada, S.; Edlbauer, H.; Lepage, H. V.; Wang, J.; Mortemousque, P.-A.; Georgiou, G.; Barnes, C. H. W.; Ford, C. J. B.; Yuan, M. Y.; Santos, P. V.; Waintal, X.; Ludwig, A.; Wieck, A. D.; Urdampilleta, M.; Meunier, T.; Bäuerle, C. Sound-Driven Single-Electron Transfer in a Circuit of Coupled Quantum Rails. Nat. Commun. 2019, 10, 4557,  DOI: 10.1038/s41467-019-12514-w
    Google Scholar
    6
    Sound-driven single-electron transfer in a circuit of coupled quantum rails
    Takada Shintaro; Edlbauer Hermann; Wang Junliang; Mortemousque Pierre-Andre; Georgiou Giorgos; Urdampilleta Matias; Meunier Tristan; Bauerle Christopher; Takada Shintaro; Lepage Hugo V; Barnes Crispin H W; Ford Christopher J B; Georgiou Giorgos; Yuan Mingyun; Santos Paulo V; Waintal Xavier; Ludwig Arne; Wieck Andreas D
    Nature communications (2019), 10 (1), 4557 ISSN:.
    Surface acoustic waves (SAWs) strongly modulate the shallow electric potential in piezoelectric materials. In semiconductor heterostructures such as GaAs/AlGaAs, SAWs can thus be employed to transfer individual electrons between distant quantum dots. This transfer mechanism makes SAW technologies a promising candidate to convey quantum information through a circuit of quantum logic gates. Here we present two essential building blocks of such a SAW-driven quantum circuit. First, we implement a directional coupler allowing to partition a flying electron arbitrarily into two paths of transportation. Second, we demonstrate a triggered single-electron source enabling synchronisation of the SAW-driven sending process. Exceeding a single-shot transfer efficiency of 99%, we show that a SAW-driven integrated circuit is feasible with single electrons on a large scale. Our results pave the way to perform quantum logic operations with flying electron qubits.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BB3MnmtFajtw%253D%253D&md5=730cde8f977be65bc8efb7a613011345
  7. 7
    Vogele, A.; Sonner, M. M.; Mayer, B.; Yuan, X.; Weiß, M.; Nysten, E. D. S.; Covre da Silva, S. F.; Rastelli, A.; Krenner, H. J. Quantum Dot Optomechanics in Suspended Nanophononic Strings. Adv. Quantum Technol. 2020, 3, 1900102,  DOI: 10.1002/qute.201900102
    Google Scholar
    7
    Quantum Dot Optomechanics in Suspended Nanophononic Strings
    Vogele, Anja; Sonner, Maximilian M.; Mayer, Benjamin; Yuan, Xueyong; Weiss, Matthias; Nysten, Emeline D. S.; Covre da Silva, Saimon F.; Rastelli, Armando; Krenner, Hubert J.
    Advanced Quantum Technologies (2020), 3 (2), 1900102CODEN: AQTDAE; ISSN:2511-9044. (Wiley-VCH Verlag GmbH & Co. KGaA)
    The optomech. coupling of quantum dots and flexural mech. modes is studied in suspended nanophononic strings. The investigated devices are designed and monolithically fabricated on an (Al)GaAs heterostructure. Radio frequency elastic waves with frequencies ranging between f=250 and 400 MHz are generated as Rayleigh surface acoustic waves on the unpatterned substrate and injected as Lamb waves in the nanophononic string. Quantum dots inside the nanophononic string exhibit a 15-fold enhanced optomech. modulation compared to those dynamically strained by the Rayleigh surface acoustic wave. Detailed finite element simulations of the phononic mode spectrum of the nanophononic string confirm that the obsd. modulation arises from valence band deformation potential coupling via shear strain. The corresponding optomech. coupling parameter is quantified to 0.15meVnm-1. This value exceeds that reported for vibrating nanorods by approx. one order of magnitude at 100 times higher frequencies. Using this value, a derived vertical displacement in the range of 10 nm is deduced from the exptl. obsd. modulation. The results represent an important step toward the creation of large scale optomech. circuits interfacing single optically active quantum dots with optical and mech. waves.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXivValsLk%253D&md5=6e0b88d6461c6519f160eed9be544619
  8. 8
    Hsiao, T.-K.; Rubino, A.; Chung, Y.; Son, S.-K.; Hou, H.; Pedrós, J.; Nasir, A.; Éthier-Majcher, G.; Stanley, M. J.; Phillips, R. T.; Mitchell, T. A.; Griffiths, J. P.; Farrer, I.; Ritchie, D. A.; Ford, C. J. B. Single-Photon Emission from Single-Electron Transport in a SAW-Driven Lateral Light-Emitting Diode. Nat. Commun. 2020, 11, 917,  DOI: 10.1038/s41467-020-14560-1
    Google Scholar
    8
    Single-photon emission from single-electron transport in a SAW-driven lateral light-emitting diode
    Hsiao, Tzu-Kan; Rubino, Antonio; Chung, Yousun; Son, Seok-Kyun; Hou, Hangtian; Pedros, Jorge; Nasir, Ateeq; Ethier-Majcher, Gabriel; Stanley, Megan J.; Phillips, Richard T.; Mitchell, Thomas A.; Griffiths, Jonathan P.; Farrer, Ian; Ritchie, David A.; Ford, Christopher J. B.
    Nature Communications (2020), 11 (1), 917CODEN: NCAOBW; ISSN:2041-1723. (Nature Research)
    Abstr.: The long-distance quantum transfer between electron-spin qubits in semiconductors is important for realizing large-scale quantum computing circuits. Electron-spin to photon-polarisation conversion is a promising technol. for achieving free-space or fiber-coupled quantum transfer. In this work, using only regular lithog. techniques on a conventional 15 nm GaAs quantum well, we demonstrate acoustically-driven generation of single photons from single electrons, without the need for a self-assembled quantum dot. In this device, a single electron is carried in a potential min. of a surface acoustic wave (SAW) and is transported to a region of holes to form an exciton. The exciton then decays and creates a single optical photon within 100 ps. This SAW-driven electroluminescence, without optimization, yields photon antibunching with g(2)(0) = 0.39 ± 0.05 in the single-electron limit (g(2)(0) = 0.63 ± 0.03 in the raw histogram). Our work marks the first step towards electron-to-photon (spin-to-polarisation) qubit conversion for scaleable quantum computing architectures.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXkvFWqurc%253D&md5=553c542335b8222131cd5da841086ac1
  9. 9
    Golter, D. A.; Oo, T.; Amezcua, M.; Stewart, K. A.; Wang, H. Optomechanical Quantum Control of a Nitrogen-Vacancy Center in Diamond. Phys. Rev. Lett. 2016, 116, 143602,  DOI: 10.1103/PhysRevLett.116.143602
    Google Scholar
    9
    Optomechanical quantum control of a nitrogen-vacancy center in diamond
    Golter, D. Andrew; Oo, Thein; Amezcua, Mayra; Stewart, Kevin A.; Wang, Hailin
    Physical Review Letters (2016), 116 (14), 143602/1-143602/6CODEN: PRLTAO; ISSN:0031-9007. (American Physical Society)
    We demonstrate optomech. quantum control of the internal electronic states of a diamond nitrogen- vacancy (NV) center in the resolved-sideband regime by coupling the NV to both optical fields and surface acoustic waves via a phonon-assisted optical transition and by taking advantage of the strong excited-state electron-phonon coupling of a NV center. Optomechanically driven Rabi oscillations as well as quantum interferences between the optomech. sideband and the direct dipole-optical transitions are realized. These studies open the door to using resolved-sideband optomech. coupling for quantum control of both the atomlike internal states and the motional states of a coupled NV-nanomech. system, leading to the development of a solid-state analog of trapped ions.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhsFeitrvO&md5=94184c9529c086d7a872c2dc42f21848
  10. 10
    Labanowski, D.; Bhallamudi, V. P.; Guo, Q.; Purser, C. M.; McCullian, M. A.; Hammel, P. C.; Salahuddin, S. Voltage-Driven, Local, and Efficient Excitation of Nitrogen-Vacancy Centers in Diamond. Sci. Adv. 2018, 4, eaat6574,  DOI: 10.1126/sciadv.aat6574
    Google Scholar
    There is no corresponding record for this reference.
  11. 11
    Maity, S.; Shao, L.; Bogdanović, S.; Meesala, S.; Sohn, Y.-I.; Sinclair, N.; Pingault, B.; Chalupnik, M.; Chia, C.; Zheng, L.; Lai, K.; Lončar, M. Coherent Acoustic Control of a Single Silicon Vacancy Spin in Diamond. Nat. Commun. 2020, 11, 193,  DOI: 10.1038/s41467-019-13822-x
    Google Scholar
    11
    Coherent acoustic control of a single silicon vacancy spin in diamond
    Maity, Smarak; Shao, Linbo; Bogdanovic, Stefan; Meesala, Srujan; Sohn, Young-Ik; Sinclair, Neil; Pingault, Benjamin; Chalupnik, Michelle; Chia, Cleaven; Zheng, Lu; Lai, Keji; Loncar, Marko
    Nature Communications (2020), 11 (1), 193CODEN: NCAOBW; ISSN:2041-1723. (Nature Research)
    Phonons are considered to be universal quantum transducers due to their ability to couple to a wide variety of quantum systems. Among these systems, solid-state point defect spins are known for being long-lived optically accessible quantum memories. Recently, it has been shown that inversion-sym. defects in diamond, such as the neg. charged silicon vacancy center (SiV), feature spin qubits that are highly susceptible to strain. Here, we leverage this strain response to achieve coherent and low-power acoustic control of a single SiV spin, and perform acoustically driven Ramsey interferometry of a single spin. Our results demonstrate an efficient method of spin control for these systems, offering a path towards strong spin-phonon coupling and phonon-mediated hybrid quantum systems.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhtFeisrc%253D&md5=ee6383a56f542663608af320e3671a2f
  12. 12
    Gustafsson, M. V.; Aref, T.; Kockum, A. F.; Ekstrom, M. K.; Johansson, G.; Delsing, P. Propagating Phonons Coupled to an Artificial Atom. Science 2014, 346, 207– 211,  DOI: 10.1126/science.1257219
    Google Scholar
    12
    Propagating phonons coupled to an artificial atom
    Gustafsson, Martin V.; Aref, Thomas; Kockum, Anton Frisk; Ekstroem, Maria K.; Johansson, Goeran; Delsing, Per
    Science (Washington, DC, United States) (2014), 346 (6206), 207-211CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)
    Quantum information can be stored in micromech. resonators, encoded as quanta of vibration known as phonons. The vibrational motion is then restricted to the stationary eigenmodes of the resonator, which thus serves as local storage for phonons. In contrast, we couple propagating phonons to an artificial atom in the quantum regime and reproduce findings from quantum optics, with sound taking over the role of light. Our results highlight the similarities between phonons and photons but also point to new opportunities arising from the characteristic features of quantum mech. sound. The low propagation speed of phonons should enable new dynamic schemes for processing quantum information, and the short wavelength allows regimes of at. physics to be explored that cannot be reached in photonic systems.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhs12nsLbK&md5=b6af97fef90331aa1c92a6dc5096e5b9
  13. 13
    Lemonde, M.-A.; Meesala, S.; Sipahigil, A.; Schuetz, M. J. A.; Lukin, M. D.; Loncar, M.; Rabl, P. Phonon Networks with Silicon-Vacancy Centers in Diamond Waveguides. Phys. Rev. Lett. 2018, 120, 213603,  DOI: 10.1103/PhysRevLett.120.213603
    Google Scholar
    13
    Phonon Networks with Silicon-Vacancy Centers in Diamond Waveguides
    Lemonde, M.-A.; Meesala, S.; Sipahigil, A.; Schuetz, M. J. A.; Lukin, M. D.; Loncar, M.; Rabl, P.
    Physical Review Letters (2018), 120 (21), 213603CODEN: PRLTAO; ISSN:1079-7114. (American Physical Society)
    A review. We propose and analyze a novel realization of a solid-state quantum network, where sepd. silicon-vacancy centers are coupled via the phonon modes of a quasi-one-dimensional diamond waveguide. In our approach, quantum states encoded in long-lived electronic spin states can be converted into propagating phonon wave packets and be reabsorbed efficiently by a distant defect center. Our anal. shows that under realistic conditions, this approach enables the implementation of high-fidelity, scalable quantum communication protocols within chip-scale spin-qubit networks. Apart from quantum information processing, this setup constitutes a novel waveguide QED platform, where strong-coupling effects between solid-state defects and individual propagating phonons can be explored at the quantum level.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXltVygsbo%253D&md5=f914b1594b5f81d952e31ebb21b83b7e
  14. 14
    Bienfait, A.; Satzinger, K. J.; Zhong, Y. P.; Chang, H.-S.; Chou, M.-H.; Conner, C. R.; Dumur, É.; Grebel, J.; Peairs, G. A.; Povey, R. G.; Cleland, A. N. Phonon-Mediated Quantum State Transfer and Remote Qubit Entanglement. Science 2019, 364, 368– 371,  DOI: 10.1126/science.aaw8415
    Google Scholar
    14
    Phonon-mediated quantum state transfer and remote qubit entanglement
    Bienfait, A.; Satzinger, K. J.; Zhong, Y. P.; Chang, H.-S.; Chou, M.-H.; Conner, C. R.; Dumur, E.; Grebel, J.; Peairs, G. A.; Povey, R. G.; Cleland, A. N.
    Science (Washington, DC, United States) (2019), 364 (6438), 368-371CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)
    Phonons, and in particular surface acoustic wave phonons, were proposed as a means to coherently couple distant solid-state quantum systems. Individual phonons in a resonant structure can be controlled and detected by superconducting qubits, enabling the coherent generation and measurement of complex stationary phonon states. The authors report the deterministic emission and capture of itinerant surface acoustic wave phonons, enabling the quantum entanglement of 2 superconducting qubits. Using a 2-mm-long acoustic quantum communication channel, equiv. to a 500-ns delay line, the authors demonstrate the emission and recapture of a phonon by 1 superconducting qubit, quantum state transfer between 2 superconducting qubits with a 67% efficiency, and, by partial transfer of a phonon, generation of an entangled Bell pair with a fidelity of 84%.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXnvFOrtbc%253D&md5=f533bce107f36ac5f1279514afed1058
  15. 15
    Devaux, T.; Tozawa, H.; Otsuka, P. H.; Mezil, S.; Tomoda, M.; Matsuda, O.; Bok, E.; Lee, S. H.; Wright, O. B. Giant Extraordinary Transmission of Acoustic Waves Through a Nanowire. Sci. Adv. 2020, 6, eaay8507,  DOI: 10.1126/sciadv.aay8507
    Google Scholar
    There is no corresponding record for this reference.
  16. 16
    Kukushkin, I. V.; Smet, J. H.; Scarola, V. W.; Umansky, V.; von Klitzing, K. Dispersion of the Excitations of Fractional Quantum Hall States. Science 2009, 324, 1044– 1047,  DOI: 10.1126/science.1171472
    Google Scholar
    16
    Dispersion of the Excitations of Fractional Quantum Hall States
    Kukushkin, Igor V.; Smet, Jurgen H.; Scarola, Vito W.; Umansky, Vladimir; von Klitzing, Klaus
    Science (Washington, DC, United States) (2009), 324 (5930), 1044-1047CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)
    The rich correlation physics in 2-dimensional (2D) electron systems is governed by the dispersion of its excitations. In the fractional quantum Hall regime, excitations involve fractionally charged quasiparticles, which exhibit dispersion min. at large momenta referred to as rotons. These rotons are difficult to access with conventional techniques because of the lack of penetration depth or sample vol. The method overcomes the limitations of conventional methods and traces the dispersion of excitations across momentum space for buried systems involving small material vol. Surface acoustic waves, launched across the 2D system, were used to allow incident radiation to trigger these excitations at large momenta. Optics probed their resonant absorption. The technique unveils the full dispersion of such excitations of several prominent correlated ground states of the 2D electron system, which has so far been inaccessible for experimentation.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXmtVKlsLw%253D&md5=8dd0e15409a6d925de3dd39bedf5a123
  17. 17
    Schubert, M.; Grossmann, M.; Ristow, O.; Hettich, M.; Bruchhausen, A.; Barretto, E. C. S.; Scheer, E.; Gusev, V.; Dekorsy, T. Spatial-Temporally Resolved High-Frequency Surface Acoustic Waves on Silicon Investigated by Femtosecond Spectroscopy. Appl. Phys. Lett. 2012, 101, 013108,  DOI: 10.1063/1.4729891
    Google Scholar
    17
    Spatial-temporally resolved high-frequency surface acoustic waves on silicon investigated by femtosecond spectroscopy
    Schubert, Martin; Grossmann, Martin; Ristow, Oliver; Hettich, Mike; Bruchhausen, Axel; Barretto, Elaine C. S.; Scheer, Elke; Gusev, Vitalyi; Dekorsy, Thomas
    Applied Physics Letters (2012), 101 (1), 013108/1-013108/4CODEN: APPLAB; ISSN:0003-6951. (American Institute of Physics)
    Various types of surface acoustic waves are generated by femtosecond pulses on bulk silicon with aluminum stripe transducers. Rayleigh and leaky longitudinal surface acoustic wave modes are detected in the time domain for various propagation distances. The modes are identified by measuring on various pitches and comparing the spectra with finite element calcns. The lifetimes of the modes are detd. quant. by spatially sepg. pump and probe beam, showing a significant difference in the lifetimes of both modes. We were able to excite and measure Rayleigh modes with frequencies of up to 90 GHz using a 100 nm period grating. (c) 2012 American Institute of Physics.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XpvVSnu7o%253D&md5=fe1ce65e95cc818c80d7ad2592cf92db
  18. 18
    Glass, N. E.; Maradudin, A. A. Leaky Surface Elastic Waves on Both Flat and Strongly Corrugated Surfaces for Isotropic, Nondissipative Media. J. Appl. Phys. 1983, 54, 796– 805,  DOI: 10.1063/1.332038
    Google Scholar
    18
    Leaky surface-elastic waves on both flat and strongly corrugated surfaces for isotropic, nondissipative media
    Glass, N. E.; Maradudin, A. A.
    Journal of Applied Physics (1983), 54 (2), 796-805CODEN: JAPIAU; ISSN:0021-8979.
    The dispersion relation for Rayleigh waves propagating across a grating, on the surface of a semi-infinite, nondissipative, isotropic elastic medium, was recently calcd. by the Rayleigh method and equivalently by a formally exact method based on the Green theorem. Now, using a complex wave-vector k or complex frequency ω in the present work, the solns. of the dispersion relation were continued into the radiative region of the kω-plane (i.e., above the bulk transverse sound line) and into the first frequency gap on the boundary of the Brillouin zone caused by the grating periodicity. Here the solns. for the surface waves have components that radiate outwardly into the bulk. The acoustic attenuation for the Rayleigh waves, calcd. from the imaginary part of complex k, agrees very well with expt.: all the obsd. peaks, including those missed by previous perturbation scattering theories, are found. Moreover, a branch is found in the dispersion relation, to which a corresponding complex soln. is also found for the flat surface, between the bulk transverse and longitudinal sound lines, that represents an intrinsically leaky flat-surface wave or surface resonance. The principal peak in the Rayleigh-wave attenuation can be assocd. with an interaction between the Rayleigh wave and this new intrinsically leaky wave.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaL3sXhtFOrt70%253D&md5=cb7916313fe200bc15e441c5cee47e47
  19. 19
    Urick, R. J. Principles of Underwater Sound; 3rd ed.; McGraw-Hill: New York, 1983.
    Google Scholar
    There is no corresponding record for this reference.
  20. 20
    Thomsen, C.; Grahn, H. T.; Maris, H. J.; Tauc, J. Surface Generation and Detection of Phonons by Picosecond Light Pulses. Phys. Rev. B: Condens. Matter Mater. Phys. 1986, 34, 4129– 4138,  DOI: 10.1103/PhysRevB.34.4129
    Google Scholar
    20
    Surface generation and detection of phonons by picosecond light pulses
    Thomsen, C.; Grahn, H. T.; Maris, H. J.; Tauc, J.
    Physical Review B: Condensed Matter and Materials Physics (1986), 34 (6), 4129-38CODEN: PRBMDO; ISSN:0163-1829.
    Expts. are reported in which ps light pulses are used to generate and detect short stress pulses (coherent longitudinal phonons). A theory is given of the generation process. The spatial shape of the stress pulse is related to the optical, electronic, and acoustical properties of the material. The stress pulses were detected through a measurement of the changes they induce in the optical reflectivity of the sample surface. The theory of this effect is discussed. Exptl. results were obtained for amorphous (a)-As2Te3, a-Ge, a-As2Se3, and Ni.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaL28Xls1Wrsr8%253D&md5=b16d6a51e535d2eb8e12c2395f01fb34
  21. 21
    Matsuda, O.; Larciprete, M. C.; Li Voti, R.; Wright, O. B. Fundamentals of Picosecond Laser. Ultrasonics 2015, 56, 3– 20,  DOI: 10.1016/j.ultras.2014.06.005
    Google Scholar
    21
    Fundamentals of picosecond laser ultrasonics
    Matsuda, Osamu; Larciprete, Maria Cristina; Li Voti, Roberto; Wright, Oliver B.
    Ultrasonics (2015), 56 (), 3-20CODEN: ULTRA3; ISSN:0041-624X. (Elsevier B.V.)
    The aim of this article is to provide an introduction to picosecond laser ultrasonics, a means by which gigahertz-terahertz ultrasonic waves can be generated and detected by ultrashort light pulses. This method can be used to characterize materials with nanometer spatial resoln. With ref. to key expts., we first review the theor. background for normal-incidence optical detection of longitudinal acoustic waves in opaque single-layer isotropic thin films. The theory is extended to handle isotropic multilayer samples, and is again compared to expt. We then review applications to anisotropic samples, including oblique-incidence optical probing, and treat the generation and detection of shear waves. Solids including metals and semiconductors are mainly discussed, although liqs. are briefly mentioned.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtFWgtrbK&md5=fc19c3b2d78ed8a93c5b59440567b594
  22. 22
    Hurley, D. H.; Telschow, K. L. Picosecond Surface Acoustic Waves Using a Suboptical Wavelength Absorption Grating. Phys. Rev. B: Condens. Matter Mater. Phys. 2002, 66 (2002), 153301,  DOI: 10.1103/PhysRevB.66.153301
    Google Scholar
    22
    Picosecond surface acoustic waves using a suboptical wavelength absorption grating
    Hurley, D. H.; Telschow, K. L.
    Physical Review B: Condensed Matter and Materials Physics (2002), 66 (15), 153301/1-153301/4CODEN: PRBMDO; ISSN:0163-1829. (American Physical Society)
    The authors demonstrated laser generation and detection of Rayleigh surface acoustic waves (SAW's) with acoustic wavelengths that are smaller than the optical wavelength of both the excitation and the detection beams. SAW generation was achieved using electron beam lithog. to modulate the surface reflectivity and hence the lateral thermal gradients on a suboptical wavelength scale. The generation and detection characteristics of two material systems were studied (Al absorption gratings on Si and GaAs substrates). The polarization sensitive absorption characteristics of the suboptical wavelength lithog. grating were exploited to explore various acoustic generation and detection schemes.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD38XovVOktbg%253D&md5=579049c4971122a1e0a7985bba2bc01e
  23. 23
    Giannetti, C.; Revaz, B.; Banfi, F.; Montagnese, M.; Ferrini, G.; Cilento, F.; Maccalli, S.; Vavassori, P.; Oliviero, G.; Bontempi, E.; Depero, L. E.; Metlushko, V.; Parmigiani, F. Thermomechanical Behavior of Surface Acoustic Waves in Ordered Arrays of Nanodisks Studied by Near-Infrared Pump-Probe Diffraction Experiments. Phys. Rev. B: Condens. Matter Mater. Phys. 2007, 76, 125413,  DOI: 10.1103/PhysRevB.76.125413
    Google Scholar
    23
    Thermomechanical behavior of surface acoustic waves in ordered arrays of nanodisks studied by near-infrared pump-probe diffraction experiments
    Giannetti, C.; Revaz, B.; Banfi, F.; Montagnese, M.; Ferrini, G.; Cilento, F.; Maccalli, S.; Vavassori, P.; Oliviero, G.; Bontempi, E.; Depero, L. E.; Metlushko, V.; Parmigiani, F.
    Physical Review B: Condensed Matter and Materials Physics (2007), 76 (12), 125413/1-125413/13CODEN: PRBMDO; ISSN:1098-0121. (American Physical Society)
    The ultrafast thermal and mech. dynamics of a two-dimensional lattice of metallic nanodisks has been studied by near-IR pump-probe diffraction measurements over a temporal range spanning from 100 fs to several nanoseconds. The expts. demonstrate that in these systems a surface acoustic wave (SAW), with a wave vector given by the reciprocal periodicity of the two-dimensional array, can be excited by ∼120 fs Ti:sapphire laser pulses. In order to clarify the interaction between the nanodisks and the substrate, numerical calcns. of the elastic eigenmodes and simulations of the thermal dynamics of the system are developed through finite-element anal. We unambiguously show that the obsd. SAW velocity shift originates from the mech. interaction between the SAWs and the nanodisks, while the correlated SAW damping is due to the energy radiation into the substrate.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXhtFeqsrrM&md5=11de60c55d018b0dcaf0b1ff6e1a461d
  24. 24
    Sadhu, J.; Lee, J. H.; Sinha, S. Frequency Shift and Attenuation of Hypersonic Surface Acoustic Phonons under Metallic Gratings. Appl. Phys. Lett. 2010, 97, 133106,  DOI: 10.1063/1.3493183
    Google Scholar
    24
    Frequency shift and attenuation of hypersonic surface acoustic phonons under metallic gratings
    Sadhu, Jyothi; Lee, J. H.; Sinha, Sanjiv
    Applied Physics Letters (2010), 97 (13), 133106/1-133106/3CODEN: APPLAB; ISSN:0003-6951. (American Institute of Physics)
    Using aluminum gratings of varying duty cycles, we report picoseconds acoustics measurements of frequency shift and attenuation in surface acoustic phonons in silicon at ∼15 GHz. We observe that the frequency shifts nonlinearly with the duty cycle, particularly in the range of 0.3 to 0.5. The data deviate from the perturbation model as a sinusoidal function of the duty cycle. The attenuation peaks at 0.5 duty cycle which is in good agreement with an eigenmode anal. of the composite structure. This work elucidates the mechanism of surface acoustic phonon scattering at periodic interfaces. (c) 2010 American Institute of Physics.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXht1agsbnE&md5=2b379c78aa6800fd18da2f3a06fc56b7
  25. 25
    Maznev, A. A.; Wright, O. B. Optical Generation of Long-Lived Surface Vibrations in a Periodic Microstructure. J. Appl. Phys. 2009, 105, 123530,  DOI: 10.1063/1.3153956
    Google Scholar
    25
    Optical generation of long-lived surface vibrations in a periodic microstructure
    Maznev, A. A.; Wright, O. B.
    Journal of Applied Physics (2009), 105 (12), 123530/1-123530/6CODEN: JAPIAU; ISSN:0021-8979. (American Institute of Physics)
    The authors use the laser-induced transient grating technique for the excitation and detection of surface vibrational modes of a periodic microstructure on a Si substrate forming a 1-dimensional phononic crystal. Two standing wave eigenmodes with zero-group velocity corresponding to the top and bottom of the bandgap in the dispersion of the zone-folded Rayleigh waves are produced by setting the spatial period of the excitation pattern to twice the structure period. These modes do not radiate acoustic energy into the substrate, yielding an enhanced lifetime. The relative amplitude of the 2 modes is controlled by the spatial phase of the excitation pattern, and discuss the dependence of the confinement time of the acoustic oscillations within the excitation area on the curvature of the dispersion surface. (c) 2009 American Institute of Physics.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXnvVyhtLY%253D&md5=adf7b00328def614cc6bb29e0be8bb79
  26. 26
    Bjornsson, M. M.; Connolly, A. B.; Mahat, S.; Rachmilowitz, B. E.; Daly, B. C.; Antonelli, G. A.; Myers, A.; Singh, K. J.; Yoo, H. J.; King, S. W. Picosecond Ultrasonic Study of Surface Acoustic Waves on Titanium Nitride Nanostructures. J. Appl. Phys. 2015, 117, 095305,  DOI: 10.1063/1.4914048
    Google Scholar
    26
    Picosecond ultrasonic study of surface acoustic waves on titanium nitride nanostructures
    Bjornsson, M. M.; Connolly, A. B.; Mahat, S.; Rachmilowitz, B. E.; Daly, B. C.; Antonelli, G. A.; Myers, A.; Singh, K. J.; Yoo, H. J.; King, S. W.
    Journal of Applied Physics (Melville, NY, United States) (2015), 117 (9), 095305/1-095305/8CODEN: JAPIAU; ISSN:0021-8979. (American Institute of Physics)
    We have measured surface acoustic waves on nanostructured TiN wires overlaid on multiple thin films on a silicon substrate using the ultrafast pump-probe technique known as picosecond ultrasonics. We find a prominent oscillation in the range of 11-54 GHz for samples with varying pitch ranging from 420 nm down to 168 nm. We find that the obsd. oscillation increases monotonically in frequency with decrease in pitch, but that the increase is not linear. By comparing our data to two-dimensional mech. simulations of the nanostructures, we find that the type of surface oscillation to which we are sensitive changes depending on the pitch of the sample. Surface waves on substrates that are loaded by thin films can take multiple forms, including Rayleigh-like waves, Sezawa waves, and radiative (leaky) surface waves. We describe evidence for detection of modes that display characteristics of these three surface wave types. (c) 2015 American Institute of Physics.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXjvF2itrs%253D&md5=ad5252163600e4f37c9d5e065ae1cfa8
  27. 27
    Sugawara, Y.; Wright, O. B.; Matsuda, O.; Takigahira, M.; Tanaka, Y.; Tamura, S.; Gusev, V. E. Watching Ripples on Crystals. Phys. Rev. Lett. 2002, 88, 185504,  DOI: 10.1103/PhysRevLett.88.185504
    Google Scholar
    27
    Watching Ripples on Crystals
    Sugawara, Y.; Wright, O. B.; Matsuda, O.; Takigahira, M.; Tanaka, Y.; Tamura, S.; Gusev, V. E.
    Physical Review Letters (2002), 88 (18), 185504/1-185504/4CODEN: PRLTAO; ISSN:0031-9007. (American Physical Society)
    The authors present a new method for imaging surface phonon focusing and dispersion at frequencies up to 1 GHz that makes use of ultrafast optical excitation and detection. Animations of coherent surface phonon wave packets emanating from a point source on isotropic and anisotropic solids are obtained with micron lateral resoln. The authors resolve rounded-square shaped wave fronts on the (100) plane of LiF and discover isolated pockets of pseudosurface wave propagation with exceptionally high group velocity in the (001) plane of TeO2. Surface phonon refraction and concn. in a minute Au pyramid is also revealed.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD38Xjt1Wltrs%253D&md5=a28cb474513f75b3ba585b0f4f4487c8
  28. 28
    Farnell, G. W.; Adler, E. L. Elastic Wave Propagation in Thin Layers; Physical Acoustics: Principles and Methods; Mason, W. P., Thurston, R. N., Eds.; Academic Press: New York, 1972; Vol. 9; pp 35– 127.
    Google Scholar
    There is no corresponding record for this reference.
  29. 29
    Grossmann, M.; Ristow, O.; Hettich, M.; He, C.; Waitz, R.; Scheer, E.; Gusev, V.; Dekorsy, T.; Schubert, M. Time-Resolved Detection of Propagating Lamb Waves in Thin Silicon Membranes with Frequencies up to 197 GHz. Appl. Phys. Lett. 2015, 106, 171904,  DOI: 10.1063/1.4919132
    Google Scholar
    29
    Time-resolved detection of propagating Lamb waves in thin silicon membranes with frequencies up to 197 GHz
    Grossmann, Martin; Ristow, Oliver; Hettich, Mike; He, Chuan; Waitz, Reimar; Scheer, Elke; Gusev, Vitalyi; Dekorsy, Thomas; Schubert, Martin
    Applied Physics Letters (2015), 106 (17), 171904/1-171904/4CODEN: APPLAB; ISSN:0003-6951. (American Institute of Physics)
    Guided acoustic waves are generated in nanopatterned Si membranes with Al gratings by optical excitation with a femtosecond laser. The spatial modulation of the photoacoustic excitation leads to Lamb waves with wavelengths detd. by the grating period. The excited Lamb waves are optically detected for different grating periods and at distances up to several μm between pump and probe spot. The measured frequencies are compared to the theor. dispersion relation for Lamb waves in thin Si membranes. Compared to surface acoustic waves in bulk Si twice higher frequencies for Lamb waves (197 GHz with a 100. nm grating) are generated in a membrane at equal grating periods. (c) 2015 American Institute of Physics.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXnt1WitrY%253D&md5=98ee49ba2db4976b0d517cd882995a73
  30. 30
    Shao, L.; Maity, S.; Zheng, L.; Wu, L.; Shams-Ansari, A.; Sohn, Y.-I.; Puma, E.; Gadalla, M. N.; Zhang, M.; Wang, C.; Hu, E.; Lai, K.; Lončar, M. Phononic Band Structure Engineering for High-Q Gigahertz Surface Acoustic Wave Resonators on Lithium Niobate. Phys. Rev. Appl. 2019, 12, 014022,  DOI: 10.1103/PhysRevApplied.12.014022
    Google Scholar
    30
    Phononic Band Structure Engineering for High-Q Gigahertz Surface Acoustic Wave Resonators on Lithium Niobate
    Shao, Linbo; Maity, Smarak; Zheng, Lu; Wu, Lue; Shams-Ansari, Amirhassan; Sohn, Young-Ik; Puma, Eric; Gadalla, M. N.; Zhang, Mian; Wang, Cheng; Hu, Evelyn; Lai, Keji; Loncar, Marko
    Physical Review Applied (2019), 12 (1), 014022CODEN: PRAHB2; ISSN:2331-7019. (American Physical Society)
    Phonons at gigahertz frequencies interact with electrons, photons, and at. systems in solids, and therefore, have extensive applications in signal processing, sensing, and quantum technologies. Surface acoustic wave (SAW) resonators that confine surface phonons can play a crucial role in such integrated phononic systems due to small mode size, low dissipation, and efficient elec. transduction. To date, it has been challenging to achieve a high quality (Q) factor and small phonon mode size for SAW resonators at gigahertz frequencies. We present a methodol. to design compact high-Q SAW resonators on lithium niobate operating at gigahertz frequencies. We exptl. verify designs and demonstrate Q factors in excess of 2x104 at room temp. (6x104 at 4 K) and mode size as low as 1.87 λ2. This is achieved by phononic band structure engineering, which provides high confinement with low mech. loss. The frequency Q products (fQ) of our SAW resonators are greater than 1013. These high-fQ and small mode size SAW resonators could enable applications in quantum phononics and integrated hybrid systems with phonons, photons, and solid-state qubits.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhvFanu7jK&md5=e7aabfbba0589d27e74ed031ed6073a7
  31. 31
    Jäckl, M.; Belotelov, V. I.; Akimov, I. A.; Savochkin, I. V.; Yakovlev, D. R.; Zvezdin, A. K.; Bayer, M. Magnon Accumulation by Clocked Laser Excitation as Source of Long-Range Spin Waves in Transparent Magnetic Films. Phys. Rev. X 2017, 7, 021009,  DOI: 10.1103/PhysRevX.7.021009
    Google Scholar
    There is no corresponding record for this reference.
  32. 32
    Couto, O. D. D., Jr.; Lazic, S.; Iikawa, F.; Stotz, J. A. H.; Jahn, U.; Hey, R.; Santos, P. V. Photon Anti-Bunching in Acoustically Pumped Quantum Dots. Nat. Photonics 2009, 3, 645– 648,  DOI: 10.1038/nphoton.2009.191
    Google Scholar
    32
    Photon anti-bunching in acoustically pumped quantum dots
    Couto, O. D. D., Jr.; Lazic, S.; Iikawa, F.; Stotz, J. A. H.; Jahn, U.; Hey, R.; Santos, P. V.
    Nature Photonics (2009), 3 (11), 645-648CODEN: NPAHBY; ISSN:1749-4885. (Nature Publishing Group)
    Although extensive research on nanostructures led to the discovery of a no. of efficient ways to confine carriers in reduced dimensions, little was done to make use of the unique properties of various nanostructures systems through coupling by the controllable transfer of carriers between them. Here, the authors demonstrate a novel approach for the controllable transfer of electrons and holes between a semiconductor quantum well and an embedded quantum dot using the moving piezoelec. potential modulation induced by an acoustic phonon. This moving potential not only transfers carriers between the quantum well and an array of quantum dots, but can also control their capture and recombination in discrete quantum dot states within the array. This feature was used to demonstrate a high-frequency, single-photon source with tunable emission energy by acoustically transferring carriers to a selected quantum dot.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXhtlCntLvF&md5=47098909de32ea9e34a587fd50d6280a
  33. 33
    Weiß, M.; Kapfinger, S.; Reichert, T.; Finley, J. J.; Wixforth, A.; Kaniber, M.; Krenner, H. J. Surface Acoustic Wave Regulated Single Photon Emission from a Coupled Quantum Dot–Nanocavity System. Appl. Phys. Lett. 2016, 109, 033105,  DOI: 10.1063/1.4959079
    Google Scholar
    33
    Surface acoustic wave regulated single photon emission from a coupled quantum dot-nanocavity system
    Weiss, M.; Kapfinger, S.; Reichert, T.; Finley, J. J.; Wixforth, A.; Kaniber, M.; Krenner, H. J.
    Applied Physics Letters (2016), 109 (3), 033105/1-033105/5CODEN: APPLAB; ISSN:0003-6951. (American Institute of Physics)
    A coupled quantum dot-nanocavity system in the weak coupling regime of cavity-quantumelectrodynamics is dynamically tuned in and out of resonance by the coherent elastic field of a fSAW ≃ 800 MHz surface acoustic wave. When the system is brought to resonance by the sound wave, light-matter interaction is strongly increased by the Purcell effect. This leads to a precisely timed single photon emission as confirmed by the second order photon correlation function, g(2). All relevant frequencies of our expt. are faithfully identified in the Fourier transform of g(2), demonstrating high fidelity regulation of the stream of single photons emitted by the system. (c) 2016 American Institute of Physics.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28Xht1WmtrvI&md5=490500c9c009f0b9f8fddcffce2a8ce0
  34. 34
    Cerda-Mendez, E. A.; Krizhanovskii, D. N.; Wouters, M.; Bradley, R.; Biermann, K.; Guda, K.; Hey, R.; Santos, P. V.; Sarkar, D.; Skolnick, M. S. Polariton Condensation in Dynamic Acoustic Lattices. Phys. Rev. Lett. 2010, 105, 116402,  DOI: 10.1103/PhysRevLett.105.116402
    Google Scholar
    34
    Polariton condensation in dynamic acoustic lattices
    Cerda-Mendez, E. A.; Krizhanovskii, D. N.; Wouters, M.; Bradley, R.; Biermann, K.; Guda, K.; Hey, R.; Santos, P. V.; Sarkar, D.; Skolnick, M. S.
    Physical Review Letters (2010), 105 (11), 116402/1-116402/4CODEN: PRLTAO; ISSN:0031-9007. (American Physical Society)
    We demonstrate that the tunable potential introduced by a surface acoustic wave on a homogeneous polariton condensate leads to fragmentation of the condensate into an array of wires which move with the acoustic velocity. Redn. of the spatial coherence of the condensate emission along the surface acoustic wave direction is attributed to the suppression of coupling between the spatially modulated condensates. Interparticle interactions obsd. at high polariton densities screen the acoustic potential, partially reversing its effect on spatial coherence.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXht1Cmt73P&md5=0d0e0329550c8a528f4143164f53133b
  35. 35
    Alexeev, E. M.; Ruiz-Tijerina, D. A.; Danovich, M.; Hamer, M. J.; Terry, D. J.; Nayak, P. K.; Ahn, S.; Pak, S.; Lee, J.; Sohn, J. I.; Molas, M. R.; Koperski, M.; Watanabe, K.; Taniguchi, T.; Novoselov, K. S.; Gorbachev, R. V.; Shin, H. S.; Fal’ko, V. I.; Tartakovskii, A. I. Resonantly Hybridized Excitons in Moire Superlattices in van der Waals Heterostructures. Nature 2019, 567, 81– 86,  DOI: 10.1038/s41586-019-0986-9
    Google Scholar
    35
    Resonantly hybridized excitons in moire´ superlattices in van der Waals heterostructures
    Alexeev, Evgeny M.; Ruiz-Tijerina, David A.; Danovich, Mark; Hamer, Matthew J.; Terry, Daniel J.; Nayak, Pramoda K.; Ahn, Seongjoon; Pak, Sangyeon; Lee, Juwon; Sohn, Jung Inn; Molas, Maciej R.; Koperski, Maciej; Watanabe, Kenji; Taniguchi, Takashi; Novoselov, Kostya S.; Gorbachev, Roman V.; Shin, Hyeon Suk; Fal'ko, Vladimir I.; Tartakovskii, Alexander I.
    Nature (London, United Kingdom) (2019), 567 (7746), 81-86CODEN: NATUAS; ISSN:0028-0836. (Nature Research)
    Atomically thin layers of two-dimensional materials can be assembled in vertical stacks that are held together by relatively weak van der Waals forces, enabling coupling between monolayer crystals with incommensurate lattices and arbitrary mutual rotation. Consequently, an overarching periodicity emerges in the local at. registry of the constituent crystal structures, which is known as a moire´ superlattice. In graphene/hexagonal boron nitride structures, the presence of a moire´ superlattice can lead to the observation of electronic minibands, whereas in twisted graphene bilayers its effects are enhanced by interlayer resonant conditions, resulting in a superconductor-insulator transition at magic twist angles. Here, using semiconducting heterostructures assembled from incommensurate molybdenum diselenide (MoSe2) and tungsten disulfide (WS2) monolayers, we demonstrate that excitonic bands can hybridize, resulting in a resonant enhancement of moire´ superlattice effects. MoSe2 and WS2 were chosen for the near-degeneracy of their conduction-band edges, in order to promote the hybridization of intra- and interlayer excitons. Hybridization manifests through a pronounced exciton energy shift as a periodic function of the interlayer rotation angle, which occurs as hybridized excitons are formed by holes that reside in MoSe2 binding to a twist-dependent superposition of electron states in the adjacent monolayers. For heterostructures in which the monolayer pairs are nearly aligned, resonant mixing of the electron states leads to pronounced effects of the geometrical moire´ pattern of the heterostructure on the dispersion and optical spectra of the hybridized excitons. Our findings underpin strategies for band-structure engineering in semiconductor devices based on van der Waals heterostructures.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXnvFGhs7o%253D&md5=a1ee6f85c149db4a32d76cd004eecfd2
  36. 36
    Kang, S.; Kim, K.; Kim, B. H.; Kim, J.; Sim, K. I.; Lee, J. U.; Lee, S.; Park, K.; Yun, S.; Kim, T.; Nag, A.; Walters, A.; Garcia-Fernandez, M.; Li, J.; Chapon, L.; Zhou, K. J.; Son, Y. W.; Kim, J. H.; Cheong, H.; Park, J. G. Coherent Many-Body Exciton in van der Waals Antiferromagnet NiPS3. Nature 2020, 583, 785– 789,  DOI: 10.1038/s41586-020-2520-5
    Google Scholar
    36
    Coherent many-body exciton in van der Waals antiferromagnet NiPS3
    Kang, Soonmin; Kim, Kangwon; Kim, Beom Hyun; Kim, Jonghyeon; Sim, Kyung Ik; Lee, Jae-Ung; Lee, Sungmin; Park, Kisoo; Yun, Seokhwan; Kim, Taehun; Nag, Abhishek; Walters, Andrew; Garcia-Fernandez, Mirian; Li, Jiemin; Chapon, Laurent; Zhou, Ke-Jin; Son, Young-Woo; Kim, Jae Hoon; Cheong, Hyeonsik; Park, Je-Geun
    Nature (London, United Kingdom) (2020), 583 (7818), 785-789CODEN: NATUAS; ISSN:0028-0836. (Nature Research)
    Abstr.: An exciton is the bosonic quasiparticle of electron-hole pairs bound by the Coulomb interaction. Bose-Einstein condensation of this exciton state has long been the subject of speculation in various model systems2,3, and examples have been found more recently in optical lattices and two-dimensional materials4-9. Unlike these conventional excitons formed from extended Bloch states4-9, excitonic bound states from intrinsically many-body localized states are rare. Here we show that a spin-orbit-entangled exciton state appears below the Neel temp. of 150 K in NiPS3, an antiferromagnetic van der Waals material. It arises intrinsically from the archetypal many-body states of the Zhang-Rice singlet10,11, and reaches a coherent state assisted by the antiferromagnetic order. Using configuration-interaction theory, we det. the origin of the coherent excitonic excitation to be a transition from a Zhang-Rice triplet to a Zhang-Rice singlet. We combine three spectroscopic tools-resonant inelastic X-ray scattering, photoluminescence and optical absorption-to characterize the exciton and to demonstrate an extremely narrow excitonic linewidth below 50 K. The discovery of the spin-orbit-entangled exciton in antiferromagnetic NiPS3 introduces van der Waals magnets as a platform to study coherent many-body excitons.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhsVWgt7vJ&md5=94d6f3b7df1d3550e6810fea9b5d30da
  37. 37
    Clark, A. E.; Hathaway, K. B.; Wun-Fogle, M.; Restorff, J. B.; Lograsso, T. A.; Keppens, V. M.; Petculescu, G.; Taylor, R. A. Extraordinary Magnetoelasticity and Lattice Softening in bcc Fe-Ga Alloys. J. Appl. Phys. 2003, 93, 8621– 8623,  DOI: 10.1063/1.1540130
    Google Scholar
    37
    Extraordinary magnetoelasticity and lattice softening in bcc. Fe-Ga alloys
    Clark, A. E.; Hathaway, K. B.; Wun-Fogle, M.; Restorff, J. B.; Lograsso, T. A.; Keppens, V. M.; Petculescu, G.; Taylor, R. A.
    Journal of Applied Physics (2003), 93 (10, Pt. 3), 8621-8623CODEN: JAPIAU; ISSN:0021-8979. (American Institute of Physics)
    Extraordinary magnetostrictive behavior was obsd. in Fe-Ga alloys with concns. of Ga between 4% and 27%. λ100 Exhibits two peaks as a function of Ga content. At room temp., λ100 reaches a max. of 265 ppm near 19% Ga and 235 ppm near 27% Ga. For compns. between 19% and 27%, λ100 drops sharply to a min. near 24% Ga and exhibits an anomalous temp. dependence, decreasing by as much as a factor of 2 at low temps. This unusual magnetostrictive behavior is interpreted from a single max. in the magnetoelastic coupling |b1| of Fe with increasing amts. of nonmagnetic Ga, combined with a strongly temp. dependent elastic shear modulus (c11-c12) which approaches zero near 27% Ga. λ111 Is significantly smaller in magnitude than λ100 over this compn. range, and has an abrupt change in sign from neg. for low Ga concns. to pos. for a concn. of Ga near 21%.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3sXjslSisbw%253D&md5=abba0fbbfec6268920622de460339107
  38. 38
    Godejohann, F.; Scherbakov, A. V.; Kukhtaruk, S. M.; Poddubny, A. N.; Yaremkevich, A. N.; Wang, M.; Nadzeyka, A.; Yakovlev, D. R.; Rushforth, A. W.; Akimov, A. V.; Bayer, M. Magnon Polaron Formed by Selectively Coupled Coherent Magnon and Phonon Modes of a Surface Patterned Ferromagnet. Phys. Rev. B: Condens. Matter Mater. Phys. 2020, 102, 144438,  DOI: 10.1103/PhysRevB.102.144438
    Google Scholar
    There is no corresponding record for this reference.
  39. 39
    Casals, B.; Statuto, N.; Foerster, M.; Hernández-Mínguez, A.; Cichelero, R.; Manshausen, P.; Mandziak, A.; Aballe, L.; Hernàndez, J. M.; Macià, F. Generation and Imaging of Magnetoacoustic Waves over Millimeter Distances. Phys. Rev. Lett. 2020, 124, 137202,  DOI: 10.1103/PhysRevLett.124.137202
    Google Scholar
    39
    Generation and Imaging of Magnetoacoustic Waves over Millimeter Distances
    Casals, Blai; Statuto, Nahuel; Foerster, Michael; Hernandez-Minguez, Alberto; Cichelero, Rafael; Manshausen, Peter; Mandziak, Ania; Aballe, Lucia; Hernandez, Joan Manel; Macia, Ferran
    Physical Review Letters (2020), 124 (13), 137202CODEN: PRLTAO; ISSN:1079-7114. (American Physical Society)
    Using hybrid piezoelec.-magnetic systems we have generated large amplitude magnetization waves mediated by magnetoelasticity with up to 25 degrees variation in the magnetization orientation. We present direct imaging and quantification of both standing and propagating acoustomagnetic waves with different wavelengths, over large distances up to several millimeters in a nickel thin film.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXptF2ltrw%253D&md5=7de416b40092731fc68f5a203ed278bf
  40. 40
    An, K.; Litvinenko, A. N.; Kohno, R.; Fuad, A. A.; Naletov, V. V.; Vila, L.; Ebels, U.; de Loubens, G.; Hurdequint, H.; Beaulieu, N.; Ben Youssef, J.; Vukadinovic, N.; Bauer, G. E. W.; Slavin, A. N.; Tiberkevich, V. S.; Klein, O. Coherent Long-Range Transfer of Angular Momentum Between Magnon Kittel Modes by Phonons. Phys. Rev. B: Condens. Matter Mater. Phys. 2020, 101, 060407,  DOI: 10.1103/PhysRevB.101.060407
    Google Scholar
    There is no corresponding record for this reference.
  41. 41
    Machado, D. H.; Crespo-Poveda, A.; Kuznetsov, A. S.; Biermann, K.; Scalvi, L. V.; Santos, P. V. Generation and Propagation of Superhigh-Frequency Bulk Acoustic Waves in GaAs. Phys. Rev. Appl. 2019, 12, 044013,  DOI: 10.1103/PhysRevApplied.12.044013
    Google Scholar
    41
    Generation and Propagation of Superhigh-Frequency Bulk Acoustic Waves in GaAs
    Machado, Diego H. O.; Crespo-Poveda, Antonio; Kuznetsov, Alexander S.; Biermann, Klaus; Scalvi, Luis V. A.; Santos, Paulo V.
    Physical Review Applied (2019), 12 (4), 044013CODEN: PRAHB2; ISSN:2331-7019. (American Physical Society)
    Coherent superhigh-frequency (SHF) vibrations provide an excellent tool for the modulation and control of excitations in semiconductors. Here, we investigate the piezoelec. generation and propagation of longitudinal bulk acoustic waves (LBAWs) with frequencies up to 20 GHz in GaAs crystals using bulk acoustic-wave resonators (BAWRs) based on piezoelec. thin ZnO films. We show that the electroacoustic conversion efficiency of the BAWRs depends sensitively on the sputtering conditions of the ZnO films. The BAWRs are then used for the study of the propagation properties of the LBAWs in GaAs in the frequency and temp. ranges from 1 to 20 GHz and 10 and 300 K, resp., which have so far not been exptl. accessed. We find that the acoustic absorption of GaAs in the temp. range from 80 K to 300 K is dominated by scattering with thermal phonons. In contrast, at lower temps., the acoustic absorption sats. at a frequency-dependent value. Expts. carried out with different propagation lengths indicate that the satn. is assocd. with losses during reflections at the sample boundaries. We also demonstrate devices with a high quality factor fabricated on top of acoustic Bragg reflectors. The results presented here prove the feasibility of high-quality acoustic resonators embedding GaAs-based nanostructures, thus opening the way for the modulation and control of their properties by elec. excited SHF LBAWs.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXit1ClurfE&md5=26621de6bf2889b74688ae82477f84d6
  42. 42
    Bartels, A.; Cerna, R.; Kistner, C.; Thoma, A.; Hudert, F.; Janke, C.; Dekorsy, T. Ultrafast Time-Domain Spectroscopy Based on High-Speed Asynchronous Optical Sampling. Rev. Sci. Instrum. 2007, 78, 035107,  DOI: 10.1063/1.2714048
    Google Scholar
    42
    Ultrafast time-domain spectroscopy based on high-speed asynchronous optical sampling
    Bartels, A.; Cerna, R.; Kistner, C.; Thoma, A.; Hudert, F.; Janke, C.; Dekorsy, T.
    Review of Scientific Instruments (2007), 78 (3), 035107/1-035107/8CODEN: RSINAK; ISSN:0034-6748. (American Institute of Physics)
    High-speed asynchronous optical sampling (ASOPS) is a novel technique for ultrafast time-domain spectroscopy (TDS). It employs two mode-locked femtosecond oscillators operating at a fixed repetition frequency difference as sources of pump and probe pulses. We present a system where the 1 GHz pulse repetition frequencies of two Ti:sapphire oscillators are linked at an offset of ΔfR = 10 kHz. As a result, their relative time delay is repetitively ramped from zero to 1 ns within a scan time of 100 μs. Mech. delay scanners common to conventional TDS systems are eliminated, thus systematic errors due to beam pointing instabilities and spot size variations are avoided when long time delays are scanned. Owing to the multikilohertz scan-rate, high-speed ASOPS permits data acquisition speeds impossible with conventional schemes. Within only 1 s of data acquisition time, a signal resoln. of 6 × 10-7 is achieved for optical pump-probe spectroscopy over a time-delay window of 1 ns. When applied to terahertz TDS, the same acquisition time yields high-resoln. terahertz spectra with 37 dB signal-to-noise ratio under nitrogen purging of the spectrometer. Spectra with 57 dB are obtained within 2 min. A new approach to perform the offset lock between the two femtosecond oscillators in a master-slave configuration using a frequency shifter at the third harmonic of the pulse repetition frequency is employed. This approach permits an unprecedented time-delay resoln. of better than 160 fs. High-speed ASOPS provides the functionality of an all-optical oscilloscope with a bandwidth in excess of 3000 GHz and with 1 GHz frequency resoln.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXltFCrsLk%253D&md5=b69fbedd803b1c85ee7b5b3f0d311318
  43. 43
    Graczykowski, B.; Mielcarek, S.; Trzaskowska, A.; Sarkar, J.; Hakonen, P.; Mroz, B. Tuning of a Hypersonic Surface Phononic Band Gap Using a Nanoscale Two-Dimensional Lattice of Pillars. Phys. Rev. B: Condens. Matter Mater. Phys. 2012, 86, 085426,  DOI: 10.1103/PhysRevB.86.085426
    Google Scholar
    43
    Tuning of a hypersonic surface phononic band gap using a nanoscale two-dimensional lattice of pillars
    Graczykowski, B.; Mielcarek, S.; Trzaskowska, A.; Sarkar, J.; Hakonen, P.; Mroz, B.
    Physical Review B: Condensed Matter and Materials Physics (2012), 86 (8), 085426/1-085426/6CODEN: PRBMDO; ISSN:1098-0121. (American Physical Society)
    We present exptl. and theor. evidence of a phononic band gap in a hypersonic range for thermally activated surface acoustic waves in two-dimensional (2D) phononic crystals. Surface Brillouin light scattering expts. were performed on the (001) surface of silicon, loaded with a 2D square lattice of 100- or 150-nm-high aluminum pillars with a spacing of 500 nm. The surface Brillouin light scattering spectra revealed a different type of surface mode, related to the modulation of the lattice structure and the mech. eigenmodes of the pillars. The exptl. data were in excellent agreement with theor. calcns. performed using the finite-element method.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhsVOnt7jI&md5=085824e293f11ca6e94631080ea56718

Cited By

ARTICLE SECTIONS
Jump To

This article is cited by 3 publications.

  1. A.V. Scherbakov, T.L. Linnik, S.M. Kukhtaruk, D.R. Yakovlev, A. Nadzeyka, A.W. Rushforth, A.V. Akimov, M. Bayer. Ultrafast magnetoacoustics in Galfenol nanostructures. Photoacoustics 2023, 34 , 100565. https://doi.org/10.1016/j.pacs.2023.100565
  2. Priya, E. R. Cardozo de Oliveira, N. D. Lanzillotti-Kimura. Perspectives on high-frequency nanomechanics, nanoacoustics, and nanophononics. Applied Physics Letters 2023, 122 (14) https://doi.org/10.1063/5.0142925
  3. Antonio Crespo-Poveda, Alexander S. Kuznetsov, Alberto Hernández-Mínguez, Abbes Tahraoui, Klaus Biermann, Paulo V. Santos. GHz guided optomechanics in planar semiconductor microcavities. Optica 2022, 9 (2) , 160. https://doi.org/10.1364/OPTICA.442162
Download PDF

  • Abstract

    High Resolution Image
    Download MS PowerPoint Slide

    Figure 1

    Figure 1. Experimental setup. (a) Basic concept: Surface waves traveling from A to C are scattered by object B, while subsurface waves freely propagate beneath the corrugated surface. (b) Scheme of the sample. (c) SEM images of the nanograting. (d) Schematic of the experimental setup for measuring phonon propagation with the pump and probe spots separated in space.

    High Resolution Image
    Download MS PowerPoint Slide

    Figure 2

    Figure 2. Experimental signals. (a) Upper panel: Signal detected when the pump and probe spots overlap in space; the inset is the FFT of the temporal signal. Lower panel: Temporal traces after filtering of the measured signal from the upper panel in three frequency bands marked in the inset. (b) Same as (a) but measured when the pump and probe spots are separated on the surface by 10 μm.

    High Resolution Image
    Download MS PowerPoint Slide

    Figure 3

    Figure 3. Dependence on the distance between source and detector. (a) FFTs obtained from the signals measured at various distances x between the pump and probe spots. Each spectrum is normalized to its maximum spectral amplitude. (b) Dependences of the spectral amplitude of the filtered signals for the Rayleigh wave (R1 mode) and the mean spectral density for the waveguide modes (W-modes) on the distance between the pump and probe spots. Solid lines show the fits of the experimental data by an exponential decay, which serve to estimate the averaged mean free path for the propagating modes. The data and fit curves are normalized for clear presentation. (c) Temporal signals after filtering in the frequency band B2 for various distances between the pump and probe spots; the inset shows the dependence of the arrival time of the bunch around 17 GHz on the distance.

    High Resolution Image
    Download MS PowerPoint Slide

    Figure 4

    Figure 4. Dispersions and spatial distributions of the hypersound modes. (a) Calculated dispersion curves for hypersound modes propagating along the surface in the structure with the Fe0.81Ga0.19 nanograting with d = 200 nm deposited on the GaAs/AlAs SL. (b) Spatial distribution of the absolute value of displacement vector (exaggerated for clarity) for the Rayleigh waves (R1 and R1*) localized in the metallic layer with the nanograting and for five waveguiding (W) phonon modes localized in the GaAs/AlAs SL.

    High Resolution Image
    Download MS PowerPoint Slide

    Figure 5

    Figure 5. W-mode wavepackets. Measured (red) and simulated (black) phonon wavepackets in the B2 spectral band for two propagation distances: x = 20 μm (a) and 40 μm (b). In the simulations, four W-modes with frequencies fw = 16.532, 17.026, 17.223, and 17.455 GHz and velocities sw = 3266, 3310, 3591, and 2881 m/s are summed.

    High Resolution Image
    Download MS PowerPoint Slide

  • References

    ARTICLE SECTIONS
    Jump To

    This article references 43 other publications.

    1. 1
      Satzinger, K. J.; Zhong, Y. P.; Chang, H.-S.; Peairs, G. A.; Bienfait, A.; Chou, M.-H.; Cleland, A. Y.; Conner, C. R.; Dumur, É.; Grebel, J.; Gutierrez, I.; November, B. H.; Povey, R. G.; Whiteley, S. J.; Awschalom, D. D.; Schuster, D. I.; Cleland, A. N. Quantum Control of Surface Acoustic-Wave Phonons. Nature 2018, 563, 661– 665,  DOI: 10.1038/s41586-018-0719-5
      Google Scholar
      1
      Quantum control of surface acoustic-wave phonons
      Satzinger, K. J.; Zhong, Y. P.; Chang, H.-S.; Peairs, G. A.; Bienfait, A.; Chou, Ming-Han; Cleland, A. Y.; Conner, C. R.; Dumur, E.; Grebel, J.; Gutierrez, I.; November, B. H.; Povey, R. G.; Whiteley, S. J.; Awschalom, D. D.; Schuster, D. I.; Cleland, A. N.
      Nature (London, United Kingdom) (2018), 563 (7733), 661-665CODEN: NATUAS; ISSN:0028-0836. (Nature Research)
      One of the hallmarks of quantum physics is the generation of non-classical quantum states and superpositions, which has been demonstrated in several quantum systems, including ions, solid-state qubits and photons. However, only indirect demonstrations of non-classical states have been achieved in mech. systems, despite the scientific appeal and tech. utility of such a capability1,2, including in quantum sensing, computation and communication applications. This is due in part to the highly linear response of most mech. systems, which makes quantum operations difficult, as well as their characteristically low frequencies, which hinder access to the quantum ground state3-7. Here we demonstrate full quantum control of the mech. state of a macroscale mech. resonator. We strongly couple a surface acoustic-wave8 resonator to a superconducting qubit, using the qubit to control and measure quantum states in the mech. resonator. We generate a non-classical superposition of the zero- and one-phonon Fock states and map this and other states using Wigner tomog.9-14. Such precise, programmable quantum control is essential to a range of applications of surface acoustic waves in the quantum limit, including the coupling of disparate quantum systems15,16.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXitlGgurzJ&md5=edd5f9d8ce869736f6569f0b5572ad85
    2. 2
      Delsing, P.; Cleland, A. N.; Schuetz, M. J. A.; Knörzer, J.; Giedke, G.; Cirac, J. I.; Srinivasan, K.; Wu, M.; Balram, K. C.; Bäuerle, C.; Meunier, T.; Ford, C. J. B.; Santos, P. V.; Cerda-Méndez, E.; Wang, H.; Krenner, H. J.; Nysten, E. D. S.; Weiß, M.; Nash, G. R.; Thevenard, L. The 2019 Surface Acoustic Waves Roadmap. J. Phys. D: Appl. Phys. 2019, 52, 353001,  DOI: 10.1088/1361-6463/ab1b04
      Google Scholar
      2
      The 2019 surface acoustic waves roadmap
      Delsing, Per; Cleland, Andrew N.; Schuetz, Martin J. A.; Knoerzer, Johannes; Giedke, Geza; Cirac, J. Ignacio; Srinivasan, Kartik; Wu, Marcelo; Balram, Krishna Coimbatore; Baeuerle, Christopher; Meunier, Tristan; Ford, Christopher J. B.; Santos, Paulo V.; Cerda-Mendez, Edgar; Wang, Hailin; Krenner, Hubert J.; Nysten, Emeline D. S.; Weiss, Matthias; Nash, Geoff R.; Thevenard, Laura; Gourdon, Catherine; Rovillain, Pauline; Marangolo, Max; Duquesne, Jean-Yves; Fischerauer, Gerhard; Ruile, Werner; Reiner, Alexander; Paschke, Ben; Denysenko, Dmytro; Volkmer, Dirk; Wixforth, Achim; Bruus, Henrik; Wiklund, Martin; Reboud, Julien; Cooper, Jonathan M.; Fu, YongQing; Brugger, Manuel S.; Rehfeldt, Florian; Westerhausen, Christoph
      Journal of Physics D: Applied Physics (2019), 52 (35), 353001CODEN: JPAPBE; ISSN:0022-3727. (IOP Publishing Ltd.)
      A review. Today, surface acoustic waves (SAWs) and bulk acoustic waves are already two of the very few phononic technologies of industrial relevance and can been found in a myriad of devices employing these nanoscale earthquakes on a chip. Acoustic radio frequency filters, for instance, are integral parts of wireless devices. SAWs in particular find applications in life sciences and microfluidics for sensing and mixing of tiny amts. of liqs. In addn. to this continuously growing no. of applications, SAWs are ideally suited to probe and control elementary excitations in condensed matter at the limit of single quantum excitations. Even collective excitations, classical or quantum are nowadays coherently interfaced by SAWs. This wide, highly diverse, interdisciplinary and continuously expanding spectrum literally unites advanced sensing and manipulation applications. Remarkably, SAW technol. is inherently multiscale and spans from single at. or nanoscopic units up even to the millimeter scale. The aim of this Roadmap is to present a snapshot of the present state of surface acoustic wave science and technol. in 2019 and provide an opinion on the challenges and opportunities that the future holds from a group of renown experts, covering the interdisciplinary key areas, ranging from fundamental quantum effects to practical applications of acoustic devices in life science.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhvVOrtrvO&md5=5cb98dbb5dc28af81ed817b8369c502d
    3. 3
      Hann, C. T.; Zou, C.-L.; Zhang, Y.; Chu, Y.; Schoelkopf, R. J.; Girvin, S. M.; Jiang, L. Hardware-Efficient Quantum Random Access Memory with Hybrid Quantum Acoustic Systems. Phys. Rev. Lett. 2019, 123, 250501,  DOI: 10.1103/PhysRevLett.123.250501
      Google Scholar
      3
      Hardware-Efficient Quantum Random Access Memory with Hybrid Quantum Acoustic Systems
      Hann, Connor T.; Zou, Chang-Ling; Zhang, Yaxing; Chu, Yiwen; Schoelkopf, Robert J.; Girvin, S. M.; Jiang, Liang
      Physical Review Letters (2019), 123 (25), 250501CODEN: PRLTAO; ISSN:1079-7114. (American Physical Society)
      Hybrid quantum systems in which acoustic resonators couple to superconducting qubits are promising quantum information platforms. High quality factors and small mode vols. make acoustic modes ideal quantum memories, while the qubit-phonon coupling enables the initialization and manipulation of quantum states. We present a scheme for quantum computing with multimode quantum acoustic systems, and based on this scheme, propose a hardware-efficient implementation of a quantum random access memory (QRAM). Quantum information is stored in high-Q phonon modes, and couplings between modes are engineered by applying off-resonant drives to a transmon qubit. In comparison to existing proposals that involve directly exciting the qubit, this scheme can offer a substantial improvement in gate fidelity for long-lived acoustic modes. We show how these engineered phonon-phonon couplings can be used to access data in superposition according to the state of designated address modes-implementing a QRAM on a single chip.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXjtFOitrc%253D&md5=1bdc7974ce70af9dd3e9b12b562afcd7
    4. 4
      Clerk, A. A.; Lehnert, K. W.; Bertet, P.; Petta, J. R.; Nakamura, Y. Hybrid Quantum Systems with Circuit Quantum Electrodynamics. Nat. Phys. 2020, 16, 257– 267,  DOI: 10.1038/s41567-020-0797-9
      Google Scholar
      4
      Hybrid quantum systems with circuit quantum electrodynamics
      Clerk, A. A.; Lehnert, K. W.; Bertet, P.; Petta, J. R.; Nakamura, Y.
      Nature Physics (2020), 16 (3), 257-267CODEN: NPAHAX; ISSN:1745-2473. (Nature Research)
      Abstr.: The rise of quantum information science has provided new perspectives on quantum mechanics, as well as a common language for quantum engineering. The focus on platforms for the manipulation and processing of quantum information bridges between different research areas in physics as well as other disciplines. Such a crossover between borders is well embodied by the development of hybrid quantum systems, where heterogeneous phys. systems are combined to leverage their individual strengths for the implementation of novel functionalities. In the microwave domain, the hybridization of various quantum degrees of freedom has been tremendously helped by superconducting quantum circuits, owing to their large zero-point field fluctuations, small dissipation, strong nonlinearity and design flexibility. These efforts take place by expanding the framework of circuit quantum electrodynamics. Here, we review recent research on the creation of hybrid quantum systems based on circuit quantum electrodynamics, encompassing mech. oscillators, quantum acoustodynamics with surface acoustic waves, quantum magnonics and coupling between superconducting circuits and ensembles or single spins.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXktFelsbw%253D&md5=4ff218a5de90caf4134466622c8ea0e4
    5. 5
      Bertrand, B.; Hermelin, S.; Takada, S.; Yamamoto, M.; Tarucha, S.; Ludwig, A.; Wieck, A. D.; Bäuerle, C.; Meunier, T. Fast Spin Information Transfer Between Distant Quantum Dots Using Individual Electrons. Nat. Nanotechnol. 2016, 11, 672– 676,  DOI: 10.1038/nnano.2016.82
      Google Scholar
      5
      Fast spin information transfer between distant quantum dots using individual electrons
      Bertrand, B.; Hermelin, S.; Takada, S.; Yamamoto, M.; Tarucha, S.; Ludwig, A.; Wieck, A. D.; Bauerle, C.; Meunier, T.
      Nature Nanotechnology (2016), 11 (8), 672-676CODEN: NNAABX; ISSN:1748-3387. (Nature Publishing Group)
      Transporting ensembles of electrons over long distances without losing their spin polarization is an important benchmark for spintronic devices. It usually requires injecting and probing spin-polarized electrons in conduction channels using ferromagnetic contacts or optical excitation. In parallel with this development, important efforts have been dedicated to achieving control of nanocircuits at the single-electron level. The detection and coherent manipulation of the spin of a single electron trapped in a quantum dot are now well established. Combined with the recently demonstrated control of the displacement of individual electrons between two distant quantum dots, these achievements allow the possibility of realizing spintronic protocols at the single-electron level. Here, we demonstrate that spin information carried by one or two electrons can be transferred between two quantum dots sepd. by a distance of 4 μm with a classical fidelity of 65%. We show that at present it is limited by spin flips occurring during the transfer procedure before and after electron displacement. Being able to encode and control information in the spin degree of freedom of a single electron while it is being transferred over distances of a few micrometres on nanosecond timescales will pave the way towards 'quantum spintronics' devices, which could be used to implement large-scale spin-based quantum information processing.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XptVSrs7w%253D&md5=0292b4872388af475677e39691d80d20
    6. 6
      Takada, S.; Edlbauer, H.; Lepage, H. V.; Wang, J.; Mortemousque, P.-A.; Georgiou, G.; Barnes, C. H. W.; Ford, C. J. B.; Yuan, M. Y.; Santos, P. V.; Waintal, X.; Ludwig, A.; Wieck, A. D.; Urdampilleta, M.; Meunier, T.; Bäuerle, C. Sound-Driven Single-Electron Transfer in a Circuit of Coupled Quantum Rails. Nat. Commun. 2019, 10, 4557,  DOI: 10.1038/s41467-019-12514-w
      Google Scholar
      6
      Sound-driven single-electron transfer in a circuit of coupled quantum rails
      Takada Shintaro; Edlbauer Hermann; Wang Junliang; Mortemousque Pierre-Andre; Georgiou Giorgos; Urdampilleta Matias; Meunier Tristan; Bauerle Christopher; Takada Shintaro; Lepage Hugo V; Barnes Crispin H W; Ford Christopher J B; Georgiou Giorgos; Yuan Mingyun; Santos Paulo V; Waintal Xavier; Ludwig Arne; Wieck Andreas D
      Nature communications (2019), 10 (1), 4557 ISSN:.
      Surface acoustic waves (SAWs) strongly modulate the shallow electric potential in piezoelectric materials. In semiconductor heterostructures such as GaAs/AlGaAs, SAWs can thus be employed to transfer individual electrons between distant quantum dots. This transfer mechanism makes SAW technologies a promising candidate to convey quantum information through a circuit of quantum logic gates. Here we present two essential building blocks of such a SAW-driven quantum circuit. First, we implement a directional coupler allowing to partition a flying electron arbitrarily into two paths of transportation. Second, we demonstrate a triggered single-electron source enabling synchronisation of the SAW-driven sending process. Exceeding a single-shot transfer efficiency of 99%, we show that a SAW-driven integrated circuit is feasible with single electrons on a large scale. Our results pave the way to perform quantum logic operations with flying electron qubits.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BB3MnmtFajtw%253D%253D&md5=730cde8f977be65bc8efb7a613011345
    7. 7
      Vogele, A.; Sonner, M. M.; Mayer, B.; Yuan, X.; Weiß, M.; Nysten, E. D. S.; Covre da Silva, S. F.; Rastelli, A.; Krenner, H. J. Quantum Dot Optomechanics in Suspended Nanophononic Strings. Adv. Quantum Technol. 2020, 3, 1900102,  DOI: 10.1002/qute.201900102
      Google Scholar
      7
      Quantum Dot Optomechanics in Suspended Nanophononic Strings
      Vogele, Anja; Sonner, Maximilian M.; Mayer, Benjamin; Yuan, Xueyong; Weiss, Matthias; Nysten, Emeline D. S.; Covre da Silva, Saimon F.; Rastelli, Armando; Krenner, Hubert J.
      Advanced Quantum Technologies (2020), 3 (2), 1900102CODEN: AQTDAE; ISSN:2511-9044. (Wiley-VCH Verlag GmbH & Co. KGaA)
      The optomech. coupling of quantum dots and flexural mech. modes is studied in suspended nanophononic strings. The investigated devices are designed and monolithically fabricated on an (Al)GaAs heterostructure. Radio frequency elastic waves with frequencies ranging between f=250 and 400 MHz are generated as Rayleigh surface acoustic waves on the unpatterned substrate and injected as Lamb waves in the nanophononic string. Quantum dots inside the nanophononic string exhibit a 15-fold enhanced optomech. modulation compared to those dynamically strained by the Rayleigh surface acoustic wave. Detailed finite element simulations of the phononic mode spectrum of the nanophononic string confirm that the obsd. modulation arises from valence band deformation potential coupling via shear strain. The corresponding optomech. coupling parameter is quantified to 0.15meVnm-1. This value exceeds that reported for vibrating nanorods by approx. one order of magnitude at 100 times higher frequencies. Using this value, a derived vertical displacement in the range of 10 nm is deduced from the exptl. obsd. modulation. The results represent an important step toward the creation of large scale optomech. circuits interfacing single optically active quantum dots with optical and mech. waves.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXivValsLk%253D&md5=6e0b88d6461c6519f160eed9be544619
    8. 8
      Hsiao, T.-K.; Rubino, A.; Chung, Y.; Son, S.-K.; Hou, H.; Pedrós, J.; Nasir, A.; Éthier-Majcher, G.; Stanley, M. J.; Phillips, R. T.; Mitchell, T. A.; Griffiths, J. P.; Farrer, I.; Ritchie, D. A.; Ford, C. J. B. Single-Photon Emission from Single-Electron Transport in a SAW-Driven Lateral Light-Emitting Diode. Nat. Commun. 2020, 11, 917,  DOI: 10.1038/s41467-020-14560-1
      Google Scholar
      8
      Single-photon emission from single-electron transport in a SAW-driven lateral light-emitting diode
      Hsiao, Tzu-Kan; Rubino, Antonio; Chung, Yousun; Son, Seok-Kyun; Hou, Hangtian; Pedros, Jorge; Nasir, Ateeq; Ethier-Majcher, Gabriel; Stanley, Megan J.; Phillips, Richard T.; Mitchell, Thomas A.; Griffiths, Jonathan P.; Farrer, Ian; Ritchie, David A.; Ford, Christopher J. B.
      Nature Communications (2020), 11 (1), 917CODEN: NCAOBW; ISSN:2041-1723. (Nature Research)
      Abstr.: The long-distance quantum transfer between electron-spin qubits in semiconductors is important for realizing large-scale quantum computing circuits. Electron-spin to photon-polarisation conversion is a promising technol. for achieving free-space or fiber-coupled quantum transfer. In this work, using only regular lithog. techniques on a conventional 15 nm GaAs quantum well, we demonstrate acoustically-driven generation of single photons from single electrons, without the need for a self-assembled quantum dot. In this device, a single electron is carried in a potential min. of a surface acoustic wave (SAW) and is transported to a region of holes to form an exciton. The exciton then decays and creates a single optical photon within 100 ps. This SAW-driven electroluminescence, without optimization, yields photon antibunching with g(2)(0) = 0.39 ± 0.05 in the single-electron limit (g(2)(0) = 0.63 ± 0.03 in the raw histogram). Our work marks the first step towards electron-to-photon (spin-to-polarisation) qubit conversion for scaleable quantum computing architectures.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXkvFWqurc%253D&md5=553c542335b8222131cd5da841086ac1
    9. 9
      Golter, D. A.; Oo, T.; Amezcua, M.; Stewart, K. A.; Wang, H. Optomechanical Quantum Control of a Nitrogen-Vacancy Center in Diamond. Phys. Rev. Lett. 2016, 116, 143602,  DOI: 10.1103/PhysRevLett.116.143602
      Google Scholar
      9
      Optomechanical quantum control of a nitrogen-vacancy center in diamond
      Golter, D. Andrew; Oo, Thein; Amezcua, Mayra; Stewart, Kevin A.; Wang, Hailin
      Physical Review Letters (2016), 116 (14), 143602/1-143602/6CODEN: PRLTAO; ISSN:0031-9007. (American Physical Society)
      We demonstrate optomech. quantum control of the internal electronic states of a diamond nitrogen- vacancy (NV) center in the resolved-sideband regime by coupling the NV to both optical fields and surface acoustic waves via a phonon-assisted optical transition and by taking advantage of the strong excited-state electron-phonon coupling of a NV center. Optomechanically driven Rabi oscillations as well as quantum interferences between the optomech. sideband and the direct dipole-optical transitions are realized. These studies open the door to using resolved-sideband optomech. coupling for quantum control of both the atomlike internal states and the motional states of a coupled NV-nanomech. system, leading to the development of a solid-state analog of trapped ions.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhsFeitrvO&md5=94184c9529c086d7a872c2dc42f21848
    10. 10
      Labanowski, D.; Bhallamudi, V. P.; Guo, Q.; Purser, C. M.; McCullian, M. A.; Hammel, P. C.; Salahuddin, S. Voltage-Driven, Local, and Efficient Excitation of Nitrogen-Vacancy Centers in Diamond. Sci. Adv. 2018, 4, eaat6574,  DOI: 10.1126/sciadv.aat6574
      Google Scholar
      There is no corresponding record for this reference.
    11. 11
      Maity, S.; Shao, L.; Bogdanović, S.; Meesala, S.; Sohn, Y.-I.; Sinclair, N.; Pingault, B.; Chalupnik, M.; Chia, C.; Zheng, L.; Lai, K.; Lončar, M. Coherent Acoustic Control of a Single Silicon Vacancy Spin in Diamond. Nat. Commun. 2020, 11, 193,  DOI: 10.1038/s41467-019-13822-x
      Google Scholar
      11
      Coherent acoustic control of a single silicon vacancy spin in diamond
      Maity, Smarak; Shao, Linbo; Bogdanovic, Stefan; Meesala, Srujan; Sohn, Young-Ik; Sinclair, Neil; Pingault, Benjamin; Chalupnik, Michelle; Chia, Cleaven; Zheng, Lu; Lai, Keji; Loncar, Marko
      Nature Communications (2020), 11 (1), 193CODEN: NCAOBW; ISSN:2041-1723. (Nature Research)
      Phonons are considered to be universal quantum transducers due to their ability to couple to a wide variety of quantum systems. Among these systems, solid-state point defect spins are known for being long-lived optically accessible quantum memories. Recently, it has been shown that inversion-sym. defects in diamond, such as the neg. charged silicon vacancy center (SiV), feature spin qubits that are highly susceptible to strain. Here, we leverage this strain response to achieve coherent and low-power acoustic control of a single SiV spin, and perform acoustically driven Ramsey interferometry of a single spin. Our results demonstrate an efficient method of spin control for these systems, offering a path towards strong spin-phonon coupling and phonon-mediated hybrid quantum systems.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhtFeisrc%253D&md5=ee6383a56f542663608af320e3671a2f
    12. 12
      Gustafsson, M. V.; Aref, T.; Kockum, A. F.; Ekstrom, M. K.; Johansson, G.; Delsing, P. Propagating Phonons Coupled to an Artificial Atom. Science 2014, 346, 207– 211,  DOI: 10.1126/science.1257219
      Google Scholar
      12
      Propagating phonons coupled to an artificial atom
      Gustafsson, Martin V.; Aref, Thomas; Kockum, Anton Frisk; Ekstroem, Maria K.; Johansson, Goeran; Delsing, Per
      Science (Washington, DC, United States) (2014), 346 (6206), 207-211CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)
      Quantum information can be stored in micromech. resonators, encoded as quanta of vibration known as phonons. The vibrational motion is then restricted to the stationary eigenmodes of the resonator, which thus serves as local storage for phonons. In contrast, we couple propagating phonons to an artificial atom in the quantum regime and reproduce findings from quantum optics, with sound taking over the role of light. Our results highlight the similarities between phonons and photons but also point to new opportunities arising from the characteristic features of quantum mech. sound. The low propagation speed of phonons should enable new dynamic schemes for processing quantum information, and the short wavelength allows regimes of at. physics to be explored that cannot be reached in photonic systems.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhs12nsLbK&md5=b6af97fef90331aa1c92a6dc5096e5b9
    13. 13
      Lemonde, M.-A.; Meesala, S.; Sipahigil, A.; Schuetz, M. J. A.; Lukin, M. D.; Loncar, M.; Rabl, P. Phonon Networks with Silicon-Vacancy Centers in Diamond Waveguides. Phys. Rev. Lett. 2018, 120, 213603,  DOI: 10.1103/PhysRevLett.120.213603
      Google Scholar
      13
      Phonon Networks with Silicon-Vacancy Centers in Diamond Waveguides
      Lemonde, M.-A.; Meesala, S.; Sipahigil, A.; Schuetz, M. J. A.; Lukin, M. D.; Loncar, M.; Rabl, P.
      Physical Review Letters (2018), 120 (21), 213603CODEN: PRLTAO; ISSN:1079-7114. (American Physical Society)
      A review. We propose and analyze a novel realization of a solid-state quantum network, where sepd. silicon-vacancy centers are coupled via the phonon modes of a quasi-one-dimensional diamond waveguide. In our approach, quantum states encoded in long-lived electronic spin states can be converted into propagating phonon wave packets and be reabsorbed efficiently by a distant defect center. Our anal. shows that under realistic conditions, this approach enables the implementation of high-fidelity, scalable quantum communication protocols within chip-scale spin-qubit networks. Apart from quantum information processing, this setup constitutes a novel waveguide QED platform, where strong-coupling effects between solid-state defects and individual propagating phonons can be explored at the quantum level.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXltVygsbo%253D&md5=f914b1594b5f81d952e31ebb21b83b7e
    14. 14
      Bienfait, A.; Satzinger, K. J.; Zhong, Y. P.; Chang, H.-S.; Chou, M.-H.; Conner, C. R.; Dumur, É.; Grebel, J.; Peairs, G. A.; Povey, R. G.; Cleland, A. N. Phonon-Mediated Quantum State Transfer and Remote Qubit Entanglement. Science 2019, 364, 368– 371,  DOI: 10.1126/science.aaw8415
      Google Scholar
      14
      Phonon-mediated quantum state transfer and remote qubit entanglement
      Bienfait, A.; Satzinger, K. J.; Zhong, Y. P.; Chang, H.-S.; Chou, M.-H.; Conner, C. R.; Dumur, E.; Grebel, J.; Peairs, G. A.; Povey, R. G.; Cleland, A. N.
      Science (Washington, DC, United States) (2019), 364 (6438), 368-371CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)
      Phonons, and in particular surface acoustic wave phonons, were proposed as a means to coherently couple distant solid-state quantum systems. Individual phonons in a resonant structure can be controlled and detected by superconducting qubits, enabling the coherent generation and measurement of complex stationary phonon states. The authors report the deterministic emission and capture of itinerant surface acoustic wave phonons, enabling the quantum entanglement of 2 superconducting qubits. Using a 2-mm-long acoustic quantum communication channel, equiv. to a 500-ns delay line, the authors demonstrate the emission and recapture of a phonon by 1 superconducting qubit, quantum state transfer between 2 superconducting qubits with a 67% efficiency, and, by partial transfer of a phonon, generation of an entangled Bell pair with a fidelity of 84%.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXnvFOrtbc%253D&md5=f533bce107f36ac5f1279514afed1058
    15. 15
      Devaux, T.; Tozawa, H.; Otsuka, P. H.; Mezil, S.; Tomoda, M.; Matsuda, O.; Bok, E.; Lee, S. H.; Wright, O. B. Giant Extraordinary Transmission of Acoustic Waves Through a Nanowire. Sci. Adv. 2020, 6, eaay8507,  DOI: 10.1126/sciadv.aay8507
      Google Scholar
      There is no corresponding record for this reference.
    16. 16
      Kukushkin, I. V.; Smet, J. H.; Scarola, V. W.; Umansky, V.; von Klitzing, K. Dispersion of the Excitations of Fractional Quantum Hall States. Science 2009, 324, 1044– 1047,  DOI: 10.1126/science.1171472
      Google Scholar
      16
      Dispersion of the Excitations of Fractional Quantum Hall States
      Kukushkin, Igor V.; Smet, Jurgen H.; Scarola, Vito W.; Umansky, Vladimir; von Klitzing, Klaus
      Science (Washington, DC, United States) (2009), 324 (5930), 1044-1047CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)
      The rich correlation physics in 2-dimensional (2D) electron systems is governed by the dispersion of its excitations. In the fractional quantum Hall regime, excitations involve fractionally charged quasiparticles, which exhibit dispersion min. at large momenta referred to as rotons. These rotons are difficult to access with conventional techniques because of the lack of penetration depth or sample vol. The method overcomes the limitations of conventional methods and traces the dispersion of excitations across momentum space for buried systems involving small material vol. Surface acoustic waves, launched across the 2D system, were used to allow incident radiation to trigger these excitations at large momenta. Optics probed their resonant absorption. The technique unveils the full dispersion of such excitations of several prominent correlated ground states of the 2D electron system, which has so far been inaccessible for experimentation.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXmtVKlsLw%253D&md5=8dd0e15409a6d925de3dd39bedf5a123
    17. 17
      Schubert, M.; Grossmann, M.; Ristow, O.; Hettich, M.; Bruchhausen, A.; Barretto, E. C. S.; Scheer, E.; Gusev, V.; Dekorsy, T. Spatial-Temporally Resolved High-Frequency Surface Acoustic Waves on Silicon Investigated by Femtosecond Spectroscopy. Appl. Phys. Lett. 2012, 101, 013108,  DOI: 10.1063/1.4729891
      Google Scholar
      17
      Spatial-temporally resolved high-frequency surface acoustic waves on silicon investigated by femtosecond spectroscopy
      Schubert, Martin; Grossmann, Martin; Ristow, Oliver; Hettich, Mike; Bruchhausen, Axel; Barretto, Elaine C. S.; Scheer, Elke; Gusev, Vitalyi; Dekorsy, Thomas
      Applied Physics Letters (2012), 101 (1), 013108/1-013108/4CODEN: APPLAB; ISSN:0003-6951. (American Institute of Physics)
      Various types of surface acoustic waves are generated by femtosecond pulses on bulk silicon with aluminum stripe transducers. Rayleigh and leaky longitudinal surface acoustic wave modes are detected in the time domain for various propagation distances. The modes are identified by measuring on various pitches and comparing the spectra with finite element calcns. The lifetimes of the modes are detd. quant. by spatially sepg. pump and probe beam, showing a significant difference in the lifetimes of both modes. We were able to excite and measure Rayleigh modes with frequencies of up to 90 GHz using a 100 nm period grating. (c) 2012 American Institute of Physics.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XpvVSnu7o%253D&md5=fe1ce65e95cc818c80d7ad2592cf92db
    18. 18
      Glass, N. E.; Maradudin, A. A. Leaky Surface Elastic Waves on Both Flat and Strongly Corrugated Surfaces for Isotropic, Nondissipative Media. J. Appl. Phys. 1983, 54, 796– 805,  DOI: 10.1063/1.332038
      Google Scholar
      18
      Leaky surface-elastic waves on both flat and strongly corrugated surfaces for isotropic, nondissipative media
      Glass, N. E.; Maradudin, A. A.
      Journal of Applied Physics (1983), 54 (2), 796-805CODEN: JAPIAU; ISSN:0021-8979.
      The dispersion relation for Rayleigh waves propagating across a grating, on the surface of a semi-infinite, nondissipative, isotropic elastic medium, was recently calcd. by the Rayleigh method and equivalently by a formally exact method based on the Green theorem. Now, using a complex wave-vector k or complex frequency ω in the present work, the solns. of the dispersion relation were continued into the radiative region of the kω-plane (i.e., above the bulk transverse sound line) and into the first frequency gap on the boundary of the Brillouin zone caused by the grating periodicity. Here the solns. for the surface waves have components that radiate outwardly into the bulk. The acoustic attenuation for the Rayleigh waves, calcd. from the imaginary part of complex k, agrees very well with expt.: all the obsd. peaks, including those missed by previous perturbation scattering theories, are found. Moreover, a branch is found in the dispersion relation, to which a corresponding complex soln. is also found for the flat surface, between the bulk transverse and longitudinal sound lines, that represents an intrinsically leaky flat-surface wave or surface resonance. The principal peak in the Rayleigh-wave attenuation can be assocd. with an interaction between the Rayleigh wave and this new intrinsically leaky wave.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaL3sXhtFOrt70%253D&md5=cb7916313fe200bc15e441c5cee47e47
    19. 19
      Urick, R. J. Principles of Underwater Sound; 3rd ed.; McGraw-Hill: New York, 1983.
      Google Scholar
      There is no corresponding record for this reference.
    20. 20
      Thomsen, C.; Grahn, H. T.; Maris, H. J.; Tauc, J. Surface Generation and Detection of Phonons by Picosecond Light Pulses. Phys. Rev. B: Condens. Matter Mater. Phys. 1986, 34, 4129– 4138,  DOI: 10.1103/PhysRevB.34.4129
      Google Scholar
      20
      Surface generation and detection of phonons by picosecond light pulses
      Thomsen, C.; Grahn, H. T.; Maris, H. J.; Tauc, J.
      Physical Review B: Condensed Matter and Materials Physics (1986), 34 (6), 4129-38CODEN: PRBMDO; ISSN:0163-1829.
      Expts. are reported in which ps light pulses are used to generate and detect short stress pulses (coherent longitudinal phonons). A theory is given of the generation process. The spatial shape of the stress pulse is related to the optical, electronic, and acoustical properties of the material. The stress pulses were detected through a measurement of the changes they induce in the optical reflectivity of the sample surface. The theory of this effect is discussed. Exptl. results were obtained for amorphous (a)-As2Te3, a-Ge, a-As2Se3, and Ni.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaL28Xls1Wrsr8%253D&md5=b16d6a51e535d2eb8e12c2395f01fb34
    21. 21
      Matsuda, O.; Larciprete, M. C.; Li Voti, R.; Wright, O. B. Fundamentals of Picosecond Laser. Ultrasonics 2015, 56, 3– 20,  DOI: 10.1016/j.ultras.2014.06.005
      Google Scholar
      21
      Fundamentals of picosecond laser ultrasonics
      Matsuda, Osamu; Larciprete, Maria Cristina; Li Voti, Roberto; Wright, Oliver B.
      Ultrasonics (2015), 56 (), 3-20CODEN: ULTRA3; ISSN:0041-624X. (Elsevier B.V.)
      The aim of this article is to provide an introduction to picosecond laser ultrasonics, a means by which gigahertz-terahertz ultrasonic waves can be generated and detected by ultrashort light pulses. This method can be used to characterize materials with nanometer spatial resoln. With ref. to key expts., we first review the theor. background for normal-incidence optical detection of longitudinal acoustic waves in opaque single-layer isotropic thin films. The theory is extended to handle isotropic multilayer samples, and is again compared to expt. We then review applications to anisotropic samples, including oblique-incidence optical probing, and treat the generation and detection of shear waves. Solids including metals and semiconductors are mainly discussed, although liqs. are briefly mentioned.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtFWgtrbK&md5=fc19c3b2d78ed8a93c5b59440567b594
    22. 22
      Hurley, D. H.; Telschow, K. L. Picosecond Surface Acoustic Waves Using a Suboptical Wavelength Absorption Grating. Phys. Rev. B: Condens. Matter Mater. Phys. 2002, 66 (2002), 153301,  DOI: 10.1103/PhysRevB.66.153301
      Google Scholar
      22
      Picosecond surface acoustic waves using a suboptical wavelength absorption grating
      Hurley, D. H.; Telschow, K. L.
      Physical Review B: Condensed Matter and Materials Physics (2002), 66 (15), 153301/1-153301/4CODEN: PRBMDO; ISSN:0163-1829. (American Physical Society)
      The authors demonstrated laser generation and detection of Rayleigh surface acoustic waves (SAW's) with acoustic wavelengths that are smaller than the optical wavelength of both the excitation and the detection beams. SAW generation was achieved using electron beam lithog. to modulate the surface reflectivity and hence the lateral thermal gradients on a suboptical wavelength scale. The generation and detection characteristics of two material systems were studied (Al absorption gratings on Si and GaAs substrates). The polarization sensitive absorption characteristics of the suboptical wavelength lithog. grating were exploited to explore various acoustic generation and detection schemes.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD38XovVOktbg%253D&md5=579049c4971122a1e0a7985bba2bc01e
    23. 23
      Giannetti, C.; Revaz, B.; Banfi, F.; Montagnese, M.; Ferrini, G.; Cilento, F.; Maccalli, S.; Vavassori, P.; Oliviero, G.; Bontempi, E.; Depero, L. E.; Metlushko, V.; Parmigiani, F. Thermomechanical Behavior of Surface Acoustic Waves in Ordered Arrays of Nanodisks Studied by Near-Infrared Pump-Probe Diffraction Experiments. Phys. Rev. B: Condens. Matter Mater. Phys. 2007, 76, 125413,  DOI: 10.1103/PhysRevB.76.125413
      Google Scholar
      23
      Thermomechanical behavior of surface acoustic waves in ordered arrays of nanodisks studied by near-infrared pump-probe diffraction experiments
      Giannetti, C.; Revaz, B.; Banfi, F.; Montagnese, M.; Ferrini, G.; Cilento, F.; Maccalli, S.; Vavassori, P.; Oliviero, G.; Bontempi, E.; Depero, L. E.; Metlushko, V.; Parmigiani, F.
      Physical Review B: Condensed Matter and Materials Physics (2007), 76 (12), 125413/1-125413/13CODEN: PRBMDO; ISSN:1098-0121. (American Physical Society)
      The ultrafast thermal and mech. dynamics of a two-dimensional lattice of metallic nanodisks has been studied by near-IR pump-probe diffraction measurements over a temporal range spanning from 100 fs to several nanoseconds. The expts. demonstrate that in these systems a surface acoustic wave (SAW), with a wave vector given by the reciprocal periodicity of the two-dimensional array, can be excited by ∼120 fs Ti:sapphire laser pulses. In order to clarify the interaction between the nanodisks and the substrate, numerical calcns. of the elastic eigenmodes and simulations of the thermal dynamics of the system are developed through finite-element anal. We unambiguously show that the obsd. SAW velocity shift originates from the mech. interaction between the SAWs and the nanodisks, while the correlated SAW damping is due to the energy radiation into the substrate.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXhtFeqsrrM&md5=11de60c55d018b0dcaf0b1ff6e1a461d
    24. 24
      Sadhu, J.; Lee, J. H.; Sinha, S. Frequency Shift and Attenuation of Hypersonic Surface Acoustic Phonons under Metallic Gratings. Appl. Phys. Lett. 2010, 97, 133106,  DOI: 10.1063/1.3493183
      Google Scholar
      24
      Frequency shift and attenuation of hypersonic surface acoustic phonons under metallic gratings
      Sadhu, Jyothi; Lee, J. H.; Sinha, Sanjiv
      Applied Physics Letters (2010), 97 (13), 133106/1-133106/3CODEN: APPLAB; ISSN:0003-6951. (American Institute of Physics)
      Using aluminum gratings of varying duty cycles, we report picoseconds acoustics measurements of frequency shift and attenuation in surface acoustic phonons in silicon at ∼15 GHz. We observe that the frequency shifts nonlinearly with the duty cycle, particularly in the range of 0.3 to 0.5. The data deviate from the perturbation model as a sinusoidal function of the duty cycle. The attenuation peaks at 0.5 duty cycle which is in good agreement with an eigenmode anal. of the composite structure. This work elucidates the mechanism of surface acoustic phonon scattering at periodic interfaces. (c) 2010 American Institute of Physics.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXht1agsbnE&md5=2b379c78aa6800fd18da2f3a06fc56b7
    25. 25
      Maznev, A. A.; Wright, O. B. Optical Generation of Long-Lived Surface Vibrations in a Periodic Microstructure. J. Appl. Phys. 2009, 105, 123530,  DOI: 10.1063/1.3153956
      Google Scholar
      25
      Optical generation of long-lived surface vibrations in a periodic microstructure
      Maznev, A. A.; Wright, O. B.
      Journal of Applied Physics (2009), 105 (12), 123530/1-123530/6CODEN: JAPIAU; ISSN:0021-8979. (American Institute of Physics)
      The authors use the laser-induced transient grating technique for the excitation and detection of surface vibrational modes of a periodic microstructure on a Si substrate forming a 1-dimensional phononic crystal. Two standing wave eigenmodes with zero-group velocity corresponding to the top and bottom of the bandgap in the dispersion of the zone-folded Rayleigh waves are produced by setting the spatial period of the excitation pattern to twice the structure period. These modes do not radiate acoustic energy into the substrate, yielding an enhanced lifetime. The relative amplitude of the 2 modes is controlled by the spatial phase of the excitation pattern, and discuss the dependence of the confinement time of the acoustic oscillations within the excitation area on the curvature of the dispersion surface. (c) 2009 American Institute of Physics.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXnvVyhtLY%253D&md5=adf7b00328def614cc6bb29e0be8bb79
    26. 26
      Bjornsson, M. M.; Connolly, A. B.; Mahat, S.; Rachmilowitz, B. E.; Daly, B. C.; Antonelli, G. A.; Myers, A.; Singh, K. J.; Yoo, H. J.; King, S. W. Picosecond Ultrasonic Study of Surface Acoustic Waves on Titanium Nitride Nanostructures. J. Appl. Phys. 2015, 117, 095305,  DOI: 10.1063/1.4914048
      Google Scholar
      26
      Picosecond ultrasonic study of surface acoustic waves on titanium nitride nanostructures
      Bjornsson, M. M.; Connolly, A. B.; Mahat, S.; Rachmilowitz, B. E.; Daly, B. C.; Antonelli, G. A.; Myers, A.; Singh, K. J.; Yoo, H. J.; King, S. W.
      Journal of Applied Physics (Melville, NY, United States) (2015), 117 (9), 095305/1-095305/8CODEN: JAPIAU; ISSN:0021-8979. (American Institute of Physics)
      We have measured surface acoustic waves on nanostructured TiN wires overlaid on multiple thin films on a silicon substrate using the ultrafast pump-probe technique known as picosecond ultrasonics. We find a prominent oscillation in the range of 11-54 GHz for samples with varying pitch ranging from 420 nm down to 168 nm. We find that the obsd. oscillation increases monotonically in frequency with decrease in pitch, but that the increase is not linear. By comparing our data to two-dimensional mech. simulations of the nanostructures, we find that the type of surface oscillation to which we are sensitive changes depending on the pitch of the sample. Surface waves on substrates that are loaded by thin films can take multiple forms, including Rayleigh-like waves, Sezawa waves, and radiative (leaky) surface waves. We describe evidence for detection of modes that display characteristics of these three surface wave types. (c) 2015 American Institute of Physics.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXjvF2itrs%253D&md5=ad5252163600e4f37c9d5e065ae1cfa8
    27. 27
      Sugawara, Y.; Wright, O. B.; Matsuda, O.; Takigahira, M.; Tanaka, Y.; Tamura, S.; Gusev, V. E. Watching Ripples on Crystals. Phys. Rev. Lett. 2002, 88, 185504,  DOI: 10.1103/PhysRevLett.88.185504
      Google Scholar
      27
      Watching Ripples on Crystals
      Sugawara, Y.; Wright, O. B.; Matsuda, O.; Takigahira, M.; Tanaka, Y.; Tamura, S.; Gusev, V. E.
      Physical Review Letters (2002), 88 (18), 185504/1-185504/4CODEN: PRLTAO; ISSN:0031-9007. (American Physical Society)
      The authors present a new method for imaging surface phonon focusing and dispersion at frequencies up to 1 GHz that makes use of ultrafast optical excitation and detection. Animations of coherent surface phonon wave packets emanating from a point source on isotropic and anisotropic solids are obtained with micron lateral resoln. The authors resolve rounded-square shaped wave fronts on the (100) plane of LiF and discover isolated pockets of pseudosurface wave propagation with exceptionally high group velocity in the (001) plane of TeO2. Surface phonon refraction and concn. in a minute Au pyramid is also revealed.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD38Xjt1Wltrs%253D&md5=a28cb474513f75b3ba585b0f4f4487c8
    28. 28
      Farnell, G. W.; Adler, E. L. Elastic Wave Propagation in Thin Layers; Physical Acoustics: Principles and Methods; Mason, W. P., Thurston, R. N., Eds.; Academic Press: New York, 1972; Vol. 9; pp 35– 127.
      Google Scholar
      There is no corresponding record for this reference.
    29. 29
      Grossmann, M.; Ristow, O.; Hettich, M.; He, C.; Waitz, R.; Scheer, E.; Gusev, V.; Dekorsy, T.; Schubert, M. Time-Resolved Detection of Propagating Lamb Waves in Thin Silicon Membranes with Frequencies up to 197 GHz. Appl. Phys. Lett. 2015, 106, 171904,  DOI: 10.1063/1.4919132
      Google Scholar
      29
      Time-resolved detection of propagating Lamb waves in thin silicon membranes with frequencies up to 197 GHz
      Grossmann, Martin; Ristow, Oliver; Hettich, Mike; He, Chuan; Waitz, Reimar; Scheer, Elke; Gusev, Vitalyi; Dekorsy, Thomas; Schubert, Martin
      Applied Physics Letters (2015), 106 (17), 171904/1-171904/4CODEN: APPLAB; ISSN:0003-6951. (American Institute of Physics)
      Guided acoustic waves are generated in nanopatterned Si membranes with Al gratings by optical excitation with a femtosecond laser. The spatial modulation of the photoacoustic excitation leads to Lamb waves with wavelengths detd. by the grating period. The excited Lamb waves are optically detected for different grating periods and at distances up to several μm between pump and probe spot. The measured frequencies are compared to the theor. dispersion relation for Lamb waves in thin Si membranes. Compared to surface acoustic waves in bulk Si twice higher frequencies for Lamb waves (197 GHz with a 100. nm grating) are generated in a membrane at equal grating periods. (c) 2015 American Institute of Physics.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXnt1WitrY%253D&md5=98ee49ba2db4976b0d517cd882995a73
    30. 30
      Shao, L.; Maity, S.; Zheng, L.; Wu, L.; Shams-Ansari, A.; Sohn, Y.-I.; Puma, E.; Gadalla, M. N.; Zhang, M.; Wang, C.; Hu, E.; Lai, K.; Lončar, M. Phononic Band Structure Engineering for High-Q Gigahertz Surface Acoustic Wave Resonators on Lithium Niobate. Phys. Rev. Appl. 2019, 12, 014022,  DOI: 10.1103/PhysRevApplied.12.014022
      Google Scholar
      30
      Phononic Band Structure Engineering for High-Q Gigahertz Surface Acoustic Wave Resonators on Lithium Niobate
      Shao, Linbo; Maity, Smarak; Zheng, Lu; Wu, Lue; Shams-Ansari, Amirhassan; Sohn, Young-Ik; Puma, Eric; Gadalla, M. N.; Zhang, Mian; Wang, Cheng; Hu, Evelyn; Lai, Keji; Loncar, Marko
      Physical Review Applied (2019), 12 (1), 014022CODEN: PRAHB2; ISSN:2331-7019. (American Physical Society)
      Phonons at gigahertz frequencies interact with electrons, photons, and at. systems in solids, and therefore, have extensive applications in signal processing, sensing, and quantum technologies. Surface acoustic wave (SAW) resonators that confine surface phonons can play a crucial role in such integrated phononic systems due to small mode size, low dissipation, and efficient elec. transduction. To date, it has been challenging to achieve a high quality (Q) factor and small phonon mode size for SAW resonators at gigahertz frequencies. We present a methodol. to design compact high-Q SAW resonators on lithium niobate operating at gigahertz frequencies. We exptl. verify designs and demonstrate Q factors in excess of 2x104 at room temp. (6x104 at 4 K) and mode size as low as 1.87 λ2. This is achieved by phononic band structure engineering, which provides high confinement with low mech. loss. The frequency Q products (fQ) of our SAW resonators are greater than 1013. These high-fQ and small mode size SAW resonators could enable applications in quantum phononics and integrated hybrid systems with phonons, photons, and solid-state qubits.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhvFanu7jK&md5=e7aabfbba0589d27e74ed031ed6073a7
    31. 31
      Jäckl, M.; Belotelov, V. I.; Akimov, I. A.; Savochkin, I. V.; Yakovlev, D. R.; Zvezdin, A. K.; Bayer, M. Magnon Accumulation by Clocked Laser Excitation as Source of Long-Range Spin Waves in Transparent Magnetic Films. Phys. Rev. X 2017, 7, 021009,  DOI: 10.1103/PhysRevX.7.021009
      Google Scholar
      There is no corresponding record for this reference.
    32. 32
      Couto, O. D. D., Jr.; Lazic, S.; Iikawa, F.; Stotz, J. A. H.; Jahn, U.; Hey, R.; Santos, P. V. Photon Anti-Bunching in Acoustically Pumped Quantum Dots. Nat. Photonics 2009, 3, 645– 648,  DOI: 10.1038/nphoton.2009.191
      Google Scholar
      32
      Photon anti-bunching in acoustically pumped quantum dots
      Couto, O. D. D., Jr.; Lazic, S.; Iikawa, F.; Stotz, J. A. H.; Jahn, U.; Hey, R.; Santos, P. V.
      Nature Photonics (2009), 3 (11), 645-648CODEN: NPAHBY; ISSN:1749-4885. (Nature Publishing Group)
      Although extensive research on nanostructures led to the discovery of a no. of efficient ways to confine carriers in reduced dimensions, little was done to make use of the unique properties of various nanostructures systems through coupling by the controllable transfer of carriers between them. Here, the authors demonstrate a novel approach for the controllable transfer of electrons and holes between a semiconductor quantum well and an embedded quantum dot using the moving piezoelec. potential modulation induced by an acoustic phonon. This moving potential not only transfers carriers between the quantum well and an array of quantum dots, but can also control their capture and recombination in discrete quantum dot states within the array. This feature was used to demonstrate a high-frequency, single-photon source with tunable emission energy by acoustically transferring carriers to a selected quantum dot.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXhtlCntLvF&md5=47098909de32ea9e34a587fd50d6280a
    33. 33
      Weiß, M.; Kapfinger, S.; Reichert, T.; Finley, J. J.; Wixforth, A.; Kaniber, M.; Krenner, H. J. Surface Acoustic Wave Regulated Single Photon Emission from a Coupled Quantum Dot–Nanocavity System. Appl. Phys. Lett. 2016, 109, 033105,  DOI: 10.1063/1.4959079
      Google Scholar
      33
      Surface acoustic wave regulated single photon emission from a coupled quantum dot-nanocavity system
      Weiss, M.; Kapfinger, S.; Reichert, T.; Finley, J. J.; Wixforth, A.; Kaniber, M.; Krenner, H. J.
      Applied Physics Letters (2016), 109 (3), 033105/1-033105/5CODEN: APPLAB; ISSN:0003-6951. (American Institute of Physics)
      A coupled quantum dot-nanocavity system in the weak coupling regime of cavity-quantumelectrodynamics is dynamically tuned in and out of resonance by the coherent elastic field of a fSAW ≃ 800 MHz surface acoustic wave. When the system is brought to resonance by the sound wave, light-matter interaction is strongly increased by the Purcell effect. This leads to a precisely timed single photon emission as confirmed by the second order photon correlation function, g(2). All relevant frequencies of our expt. are faithfully identified in the Fourier transform of g(2), demonstrating high fidelity regulation of the stream of single photons emitted by the system. (c) 2016 American Institute of Physics.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28Xht1WmtrvI&md5=490500c9c009f0b9f8fddcffce2a8ce0
    34. 34
      Cerda-Mendez, E. A.; Krizhanovskii, D. N.; Wouters, M.; Bradley, R.; Biermann, K.; Guda, K.; Hey, R.; Santos, P. V.; Sarkar, D.; Skolnick, M. S. Polariton Condensation in Dynamic Acoustic Lattices. Phys. Rev. Lett. 2010, 105, 116402,  DOI: 10.1103/PhysRevLett.105.116402
      Google Scholar
      34
      Polariton condensation in dynamic acoustic lattices
      Cerda-Mendez, E. A.; Krizhanovskii, D. N.; Wouters, M.; Bradley, R.; Biermann, K.; Guda, K.; Hey, R.; Santos, P. V.; Sarkar, D.; Skolnick, M. S.
      Physical Review Letters (2010), 105 (11), 116402/1-116402/4CODEN: PRLTAO; ISSN:0031-9007. (American Physical Society)
      We demonstrate that the tunable potential introduced by a surface acoustic wave on a homogeneous polariton condensate leads to fragmentation of the condensate into an array of wires which move with the acoustic velocity. Redn. of the spatial coherence of the condensate emission along the surface acoustic wave direction is attributed to the suppression of coupling between the spatially modulated condensates. Interparticle interactions obsd. at high polariton densities screen the acoustic potential, partially reversing its effect on spatial coherence.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXht1Cmt73P&md5=0d0e0329550c8a528f4143164f53133b
    35. 35
      Alexeev, E. M.; Ruiz-Tijerina, D. A.; Danovich, M.; Hamer, M. J.; Terry, D. J.; Nayak, P. K.; Ahn, S.; Pak, S.; Lee, J.; Sohn, J. I.; Molas, M. R.; Koperski, M.; Watanabe, K.; Taniguchi, T.; Novoselov, K. S.; Gorbachev, R. V.; Shin, H. S.; Fal’ko, V. I.; Tartakovskii, A. I. Resonantly Hybridized Excitons in Moire Superlattices in van der Waals Heterostructures. Nature 2019, 567, 81– 86,  DOI: 10.1038/s41586-019-0986-9
      Google Scholar
      35
      Resonantly hybridized excitons in moire´ superlattices in van der Waals heterostructures
      Alexeev, Evgeny M.; Ruiz-Tijerina, David A.; Danovich, Mark; Hamer, Matthew J.; Terry, Daniel J.; Nayak, Pramoda K.; Ahn, Seongjoon; Pak, Sangyeon; Lee, Juwon; Sohn, Jung Inn; Molas, Maciej R.; Koperski, Maciej; Watanabe, Kenji; Taniguchi, Takashi; Novoselov, Kostya S.; Gorbachev, Roman V.; Shin, Hyeon Suk; Fal'ko, Vladimir I.; Tartakovskii, Alexander I.
      Nature (London, United Kingdom) (2019), 567 (7746), 81-86CODEN: NATUAS; ISSN:0028-0836. (Nature Research)
      Atomically thin layers of two-dimensional materials can be assembled in vertical stacks that are held together by relatively weak van der Waals forces, enabling coupling between monolayer crystals with incommensurate lattices and arbitrary mutual rotation. Consequently, an overarching periodicity emerges in the local at. registry of the constituent crystal structures, which is known as a moire´ superlattice. In graphene/hexagonal boron nitride structures, the presence of a moire´ superlattice can lead to the observation of electronic minibands, whereas in twisted graphene bilayers its effects are enhanced by interlayer resonant conditions, resulting in a superconductor-insulator transition at magic twist angles. Here, using semiconducting heterostructures assembled from incommensurate molybdenum diselenide (MoSe2) and tungsten disulfide (WS2) monolayers, we demonstrate that excitonic bands can hybridize, resulting in a resonant enhancement of moire´ superlattice effects. MoSe2 and WS2 were chosen for the near-degeneracy of their conduction-band edges, in order to promote the hybridization of intra- and interlayer excitons. Hybridization manifests through a pronounced exciton energy shift as a periodic function of the interlayer rotation angle, which occurs as hybridized excitons are formed by holes that reside in MoSe2 binding to a twist-dependent superposition of electron states in the adjacent monolayers. For heterostructures in which the monolayer pairs are nearly aligned, resonant mixing of the electron states leads to pronounced effects of the geometrical moire´ pattern of the heterostructure on the dispersion and optical spectra of the hybridized excitons. Our findings underpin strategies for band-structure engineering in semiconductor devices based on van der Waals heterostructures.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXnvFGhs7o%253D&md5=a1ee6f85c149db4a32d76cd004eecfd2
    36. 36
      Kang, S.; Kim, K.; Kim, B. H.; Kim, J.; Sim, K. I.; Lee, J. U.; Lee, S.; Park, K.; Yun, S.; Kim, T.; Nag, A.; Walters, A.; Garcia-Fernandez, M.; Li, J.; Chapon, L.; Zhou, K. J.; Son, Y. W.; Kim, J. H.; Cheong, H.; Park, J. G. Coherent Many-Body Exciton in van der Waals Antiferromagnet NiPS3. Nature 2020, 583, 785– 789,  DOI: 10.1038/s41586-020-2520-5
      Google Scholar
      36
      Coherent many-body exciton in van der Waals antiferromagnet NiPS3
      Kang, Soonmin; Kim, Kangwon; Kim, Beom Hyun; Kim, Jonghyeon; Sim, Kyung Ik; Lee, Jae-Ung; Lee, Sungmin; Park, Kisoo; Yun, Seokhwan; Kim, Taehun; Nag, Abhishek; Walters, Andrew; Garcia-Fernandez, Mirian; Li, Jiemin; Chapon, Laurent; Zhou, Ke-Jin; Son, Young-Woo; Kim, Jae Hoon; Cheong, Hyeonsik; Park, Je-Geun
      Nature (London, United Kingdom) (2020), 583 (7818), 785-789CODEN: NATUAS; ISSN:0028-0836. (Nature Research)
      Abstr.: An exciton is the bosonic quasiparticle of electron-hole pairs bound by the Coulomb interaction. Bose-Einstein condensation of this exciton state has long been the subject of speculation in various model systems2,3, and examples have been found more recently in optical lattices and two-dimensional materials4-9. Unlike these conventional excitons formed from extended Bloch states4-9, excitonic bound states from intrinsically many-body localized states are rare. Here we show that a spin-orbit-entangled exciton state appears below the Neel temp. of 150 K in NiPS3, an antiferromagnetic van der Waals material. It arises intrinsically from the archetypal many-body states of the Zhang-Rice singlet10,11, and reaches a coherent state assisted by the antiferromagnetic order. Using configuration-interaction theory, we det. the origin of the coherent excitonic excitation to be a transition from a Zhang-Rice triplet to a Zhang-Rice singlet. We combine three spectroscopic tools-resonant inelastic X-ray scattering, photoluminescence and optical absorption-to characterize the exciton and to demonstrate an extremely narrow excitonic linewidth below 50 K. The discovery of the spin-orbit-entangled exciton in antiferromagnetic NiPS3 introduces van der Waals magnets as a platform to study coherent many-body excitons.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhsVWgt7vJ&md5=94d6f3b7df1d3550e6810fea9b5d30da
    37. 37
      Clark, A. E.; Hathaway, K. B.; Wun-Fogle, M.; Restorff, J. B.; Lograsso, T. A.; Keppens, V. M.; Petculescu, G.; Taylor, R. A. Extraordinary Magnetoelasticity and Lattice Softening in bcc Fe-Ga Alloys. J. Appl. Phys. 2003, 93, 8621– 8623,  DOI: 10.1063/1.1540130
      Google Scholar
      37
      Extraordinary magnetoelasticity and lattice softening in bcc. Fe-Ga alloys
      Clark, A. E.; Hathaway, K. B.; Wun-Fogle, M.; Restorff, J. B.; Lograsso, T. A.; Keppens, V. M.; Petculescu, G.; Taylor, R. A.
      Journal of Applied Physics (2003), 93 (10, Pt. 3), 8621-8623CODEN: JAPIAU; ISSN:0021-8979. (American Institute of Physics)
      Extraordinary magnetostrictive behavior was obsd. in Fe-Ga alloys with concns. of Ga between 4% and 27%. λ100 Exhibits two peaks as a function of Ga content. At room temp., λ100 reaches a max. of 265 ppm near 19% Ga and 235 ppm near 27% Ga. For compns. between 19% and 27%, λ100 drops sharply to a min. near 24% Ga and exhibits an anomalous temp. dependence, decreasing by as much as a factor of 2 at low temps. This unusual magnetostrictive behavior is interpreted from a single max. in the magnetoelastic coupling |b1| of Fe with increasing amts. of nonmagnetic Ga, combined with a strongly temp. dependent elastic shear modulus (c11-c12) which approaches zero near 27% Ga. λ111 Is significantly smaller in magnitude than λ100 over this compn. range, and has an abrupt change in sign from neg. for low Ga concns. to pos. for a concn. of Ga near 21%.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3sXjslSisbw%253D&md5=abba0fbbfec6268920622de460339107
    38. 38
      Godejohann, F.; Scherbakov, A. V.; Kukhtaruk, S. M.; Poddubny, A. N.; Yaremkevich, A. N.; Wang, M.; Nadzeyka, A.; Yakovlev, D. R.; Rushforth, A. W.; Akimov, A. V.; Bayer, M. Magnon Polaron Formed by Selectively Coupled Coherent Magnon and Phonon Modes of a Surface Patterned Ferromagnet. Phys. Rev. B: Condens. Matter Mater. Phys. 2020, 102, 144438,  DOI: 10.1103/PhysRevB.102.144438
      Google Scholar
      There is no corresponding record for this reference.
    39. 39
      Casals, B.; Statuto, N.; Foerster, M.; Hernández-Mínguez, A.; Cichelero, R.; Manshausen, P.; Mandziak, A.; Aballe, L.; Hernàndez, J. M.; Macià, F. Generation and Imaging of Magnetoacoustic Waves over Millimeter Distances. Phys. Rev. Lett. 2020, 124, 137202,  DOI: 10.1103/PhysRevLett.124.137202
      Google Scholar
      39
      Generation and Imaging of Magnetoacoustic Waves over Millimeter Distances
      Casals, Blai; Statuto, Nahuel; Foerster, Michael; Hernandez-Minguez, Alberto; Cichelero, Rafael; Manshausen, Peter; Mandziak, Ania; Aballe, Lucia; Hernandez, Joan Manel; Macia, Ferran
      Physical Review Letters (2020), 124 (13), 137202CODEN: PRLTAO; ISSN:1079-7114. (American Physical Society)
      Using hybrid piezoelec.-magnetic systems we have generated large amplitude magnetization waves mediated by magnetoelasticity with up to 25 degrees variation in the magnetization orientation. We present direct imaging and quantification of both standing and propagating acoustomagnetic waves with different wavelengths, over large distances up to several millimeters in a nickel thin film.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXptF2ltrw%253D&md5=7de416b40092731fc68f5a203ed278bf
    40. 40
      An, K.; Litvinenko, A. N.; Kohno, R.; Fuad, A. A.; Naletov, V. V.; Vila, L.; Ebels, U.; de Loubens, G.; Hurdequint, H.; Beaulieu, N.; Ben Youssef, J.; Vukadinovic, N.; Bauer, G. E. W.; Slavin, A. N.; Tiberkevich, V. S.; Klein, O. Coherent Long-Range Transfer of Angular Momentum Between Magnon Kittel Modes by Phonons. Phys. Rev. B: Condens. Matter Mater. Phys. 2020, 101, 060407,  DOI: 10.1103/PhysRevB.101.060407
      Google Scholar
      There is no corresponding record for this reference.
    41. 41
      Machado, D. H.; Crespo-Poveda, A.; Kuznetsov, A. S.; Biermann, K.; Scalvi, L. V.; Santos, P. V. Generation and Propagation of Superhigh-Frequency Bulk Acoustic Waves in GaAs. Phys. Rev. Appl. 2019, 12, 044013,  DOI: 10.1103/PhysRevApplied.12.044013
      Google Scholar
      41
      Generation and Propagation of Superhigh-Frequency Bulk Acoustic Waves in GaAs
      Machado, Diego H. O.; Crespo-Poveda, Antonio; Kuznetsov, Alexander S.; Biermann, Klaus; Scalvi, Luis V. A.; Santos, Paulo V.
      Physical Review Applied (2019), 12 (4), 044013CODEN: PRAHB2; ISSN:2331-7019. (American Physical Society)
      Coherent superhigh-frequency (SHF) vibrations provide an excellent tool for the modulation and control of excitations in semiconductors. Here, we investigate the piezoelec. generation and propagation of longitudinal bulk acoustic waves (LBAWs) with frequencies up to 20 GHz in GaAs crystals using bulk acoustic-wave resonators (BAWRs) based on piezoelec. thin ZnO films. We show that the electroacoustic conversion efficiency of the BAWRs depends sensitively on the sputtering conditions of the ZnO films. The BAWRs are then used for the study of the propagation properties of the LBAWs in GaAs in the frequency and temp. ranges from 1 to 20 GHz and 10 and 300 K, resp., which have so far not been exptl. accessed. We find that the acoustic absorption of GaAs in the temp. range from 80 K to 300 K is dominated by scattering with thermal phonons. In contrast, at lower temps., the acoustic absorption sats. at a frequency-dependent value. Expts. carried out with different propagation lengths indicate that the satn. is assocd. with losses during reflections at the sample boundaries. We also demonstrate devices with a high quality factor fabricated on top of acoustic Bragg reflectors. The results presented here prove the feasibility of high-quality acoustic resonators embedding GaAs-based nanostructures, thus opening the way for the modulation and control of their properties by elec. excited SHF LBAWs.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXit1ClurfE&md5=26621de6bf2889b74688ae82477f84d6
    42. 42
      Bartels, A.; Cerna, R.; Kistner, C.; Thoma, A.; Hudert, F.; Janke, C.; Dekorsy, T. Ultrafast Time-Domain Spectroscopy Based on High-Speed Asynchronous Optical Sampling. Rev. Sci. Instrum. 2007, 78, 035107,  DOI: 10.1063/1.2714048
      Google Scholar
      42
      Ultrafast time-domain spectroscopy based on high-speed asynchronous optical sampling
      Bartels, A.; Cerna, R.; Kistner, C.; Thoma, A.; Hudert, F.; Janke, C.; Dekorsy, T.
      Review of Scientific Instruments (2007), 78 (3), 035107/1-035107/8CODEN: RSINAK; ISSN:0034-6748. (American Institute of Physics)
      High-speed asynchronous optical sampling (ASOPS) is a novel technique for ultrafast time-domain spectroscopy (TDS). It employs two mode-locked femtosecond oscillators operating at a fixed repetition frequency difference as sources of pump and probe pulses. We present a system where the 1 GHz pulse repetition frequencies of two Ti:sapphire oscillators are linked at an offset of ΔfR = 10 kHz. As a result, their relative time delay is repetitively ramped from zero to 1 ns within a scan time of 100 μs. Mech. delay scanners common to conventional TDS systems are eliminated, thus systematic errors due to beam pointing instabilities and spot size variations are avoided when long time delays are scanned. Owing to the multikilohertz scan-rate, high-speed ASOPS permits data acquisition speeds impossible with conventional schemes. Within only 1 s of data acquisition time, a signal resoln. of 6 × 10-7 is achieved for optical pump-probe spectroscopy over a time-delay window of 1 ns. When applied to terahertz TDS, the same acquisition time yields high-resoln. terahertz spectra with 37 dB signal-to-noise ratio under nitrogen purging of the spectrometer. Spectra with 57 dB are obtained within 2 min. A new approach to perform the offset lock between the two femtosecond oscillators in a master-slave configuration using a frequency shifter at the third harmonic of the pulse repetition frequency is employed. This approach permits an unprecedented time-delay resoln. of better than 160 fs. High-speed ASOPS provides the functionality of an all-optical oscilloscope with a bandwidth in excess of 3000 GHz and with 1 GHz frequency resoln.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXltFCrsLk%253D&md5=b69fbedd803b1c85ee7b5b3f0d311318
    43. 43
      Graczykowski, B.; Mielcarek, S.; Trzaskowska, A.; Sarkar, J.; Hakonen, P.; Mroz, B. Tuning of a Hypersonic Surface Phononic Band Gap Using a Nanoscale Two-Dimensional Lattice of Pillars. Phys. Rev. B: Condens. Matter Mater. Phys. 2012, 86, 085426,  DOI: 10.1103/PhysRevB.86.085426
      Google Scholar
      43
      Tuning of a hypersonic surface phononic band gap using a nanoscale two-dimensional lattice of pillars
      Graczykowski, B.; Mielcarek, S.; Trzaskowska, A.; Sarkar, J.; Hakonen, P.; Mroz, B.
      Physical Review B: Condensed Matter and Materials Physics (2012), 86 (8), 085426/1-085426/6CODEN: PRBMDO; ISSN:1098-0121. (American Physical Society)
      We present exptl. and theor. evidence of a phononic band gap in a hypersonic range for thermally activated surface acoustic waves in two-dimensional (2D) phononic crystals. Surface Brillouin light scattering expts. were performed on the (001) surface of silicon, loaded with a 2D square lattice of 100- or 150-nm-high aluminum pillars with a spacing of 500 nm. The surface Brillouin light scattering spectra revealed a different type of surface mode, related to the modulation of the lattice structure and the mech. eigenmodes of the pillars. The exptl. data were in excellent agreement with theor. calcns. performed using the finite-element method.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhsVOnt7jI&md5=085824e293f11ca6e94631080ea56718

  • Supporting Information

    Supporting Information

    ARTICLE SECTIONS
    Jump To

    The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsnano.0c09475.

    • Experimental and theoretical data for all the studied samples; elastic equations and their semi-analytical solutions for an unpatterned metallic film on a GaAs substrate and on a SL; spatial distributions and main parameters of the W-modes for the grating with 200 nm period (PDF)

    • Video 1: Spatial-temporal modeling (COMSOL Multiphysics) of the hypersound propagation in the structure with a GaAs/AlAs SL and a Fe0.81Ga0.19 nanograting with period d = 200 nm after excitation by the pump pulse. The color map illustrates the time derivative of the z-component of the displacement vector. The black horizontal lines show the boundaries between the different materials of the structure (MOV)

    • Video 2: Temporal evolution of the guided wavepacket consisting of four W-modes with frequencies fw= 16.532, 17.026, 17.223, and 17.455 GHz and corresponding velocities sw= 3266, 3310, 3591, and 2881 m/s, taken from the calculated dispersions. The modes are simultaneously excited at the excitation spot with the same amplitudes, spatial distributions, and initial phases (MOV)


    Terms & Conditions

    Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.

PDF [ 5MB]

Pair your accounts.

Export articles to Mendeley

Get article recommendations from ACS based on references in your Mendeley library.

Pair your accounts.

Export articles to Mendeley

Get article recommendations from ACS based on references in your Mendeley library.

You’ve supercharged your research process with ACS and Mendeley!

STEP 1:
Click to create an ACS ID

Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

MENDELEY PAIRING EXPIRED
Your Mendeley pairing has expired. Please reconnect