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Charge Configuration Memory Devices: Energy Efficiency and Switching Speed

  • Anze Mraz*
    Anze Mraz
    Complex Matter Department F7, Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia
    Faculty of Electrical Engineering, University of Ljubljana, Tržaška cesta 25, 1000 Ljubljana, Slovenia
    *Email: [email protected]
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    Orcidhttps://orcid.org/0000-0002-8030-2628
  • , 
  • Rok Venturini
    Rok Venturini
    Complex Matter Department F7, Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia
    Faculty of Mathematics and Physics, University of Ljubljana, Jadranska cesta 19, 1000 Ljubljana, Slovenia
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  • , 
  • Damjan Svetin
    Damjan Svetin
    Complex Matter Department F7, Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia
    CENN Nanocenter, Jamova cesta 39, 1000 Ljubljana, Slovenia
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  • , 
  • Vitomir Sever
    Vitomir Sever
    Complex Matter Department F7, Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia
    More by Vitomir Sever
  • , 
  • Ian Aleksander Mihailovic
    Ian Aleksander Mihailovic
    Complex Matter Department F7, Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia
    More by Ian Aleksander Mihailovic
  • , 
  • Igor Vaskivskyi
    Igor Vaskivskyi
    Complex Matter Department F7, Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia
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  • , 
  • Bojan Ambrozic
    Bojan Ambrozic
    CENN Nanocenter, Jamova cesta 39, 1000 Ljubljana, Slovenia
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  • , 
  • Goran Dražić
    Goran Dražić
    Jozef Stefan International Postgraduate School, Jamova cesta 39, 1000 Ljubljana, Slovenia
    Department of Materials Chemistry, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
    More by Goran Dražić
    Orcidhttps://orcid.org/0000-0001-7809-8050
  • , 
  • Maria D’Antuono
    Maria D’Antuono
    Dipartimento di Fisica “Ettore Pancini”, Università di Napoli Federico II, Monte S. Angelo via Cinthia, 80126 Napoli, Italy
    CNR-SPIN, Complesso Monte Sant’Angelo, Via Cinthia, 80126 Napoli, Italy
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  • , 
  • Daniela Stornaiuolo
    Daniela Stornaiuolo
    CNR-SPIN, Complesso Monte Sant’Angelo, Via Cinthia, 80126 Napoli, Italy
    Dipartimento di Fisica “Ettore Pancini”, Università di Napoli Federico II, Monte S. Angelo via Cinthia, 80126 Napoli, Italy
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  • , 
  • Francesco Tafuri
    Francesco Tafuri
    Dipartimento di Fisica “Ettore Pancini”, Università di Napoli Federico II, Monte S. Angelo via Cinthia, 80126 Napoli, Italy
    CNR-Istituto Nazionale di Ottica (CNR-INO), Largo Enrico Fermi 6, 50125 Florence, Italy
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  • , 
  • Dimitrios Kazazis
    Dimitrios Kazazis
    Paul Scherrer Institute, Forschungsstrasse 111, 5232 Villigen PSI, Switzerland
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    Orcidhttps://orcid.org/0000-0002-2124-2813
  • , 
  • Jan Ravnik
    Jan Ravnik
    Paul Scherrer Institute, Forschungsstrasse 111, 5232 Villigen PSI, Switzerland
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  • , 
  • Yasin Ekinci
    Yasin Ekinci
    Paul Scherrer Institute, Forschungsstrasse 111, 5232 Villigen PSI, Switzerland
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  • , and 
  • Dragan Mihailovic
    Dragan Mihailovic
    Complex Matter Department F7, Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia
    CENN Nanocenter, Jamova cesta 39, 1000 Ljubljana, Slovenia
    Faculty of Mathematics and Physics, University of Ljubljana, Jadranska cesta 19, 1000 Ljubljana, Slovenia
    Jozef Stefan International Postgraduate School, Jamova cesta 39, 1000 Ljubljana, Slovenia
    More by Dragan Mihailovic
Cite this: Nano Lett. 2022, 22, 12, 4814–4821
Publication Date (Web):June 10, 2022
https://doi.org/10.1021/acs.nanolett.2c01116

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Abstract

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Current trends in data processing have given impetus for an intense search of new concepts of memory devices with emphasis on efficiency, speed, and scalability. A promising new approach to memory storage is based on resistance switching between charge-ordered domain states in the layered dichalcogenide 1T-TaS2. Here we investigate the energy efficiency scaling of such charge configuration memory (CCM) devices as a function of device size and data write time τW as well as other parameters that have bearing on efficient device operation. We find that switching energy efficiency scales approximately linearly with both quantities over multiple decades, departing from linearity only when τW approaches the ∼0.5 ps intrinsic switching limit. Compared to current state of the art memory devices, CCM devices are found to be much faster and significantly more energy efficient, demonstrated here with two-terminal switching using 2.2 fJ, 16 ps electrical pulses.

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Research in the area of novel memory devices has been intense in the recent decades, but there have been few breakthroughs that have led to implementation. (1−3) As a result, technologies such as cryocomputing that promise large improvements in energy consumption have been seriously hindered by the absence of a suitable fast and energy-efficient memory for more than two decades. (4,5) As an alternative to modern magnetic devices, manipulating charge, rather than spins, for data storage could be more efficient because it can be directly driven by electrical charge injection that promises to be extremely fast and efficient. Unfortunately, the direct coupling of an electronic two-level system to lattice degrees of freedom causes rapid state decoherence and dissipation, which fundamentally limits charge-storage based memory concepts. As an apparent solution to this problem, it was shown recently that topological protection that stabilizes different charge density wave (CDW) domain states in the quasi-2D layered transition metal chalcogenide 1T-TaS2 can be used for memory devices. (6,7) The basic mechanism for such a charge configuration memory (CCM) was shown to be unique to this material, (7−9) involving reversible charge reconfiguration from an insulating, spatially uniform CDW state to a metallic domain state (10) with accompanying restacking of the CDW along the direction perpendicular to the layers. (11) To develop the CCM concept into viable practical devices, a better understanding of the device characteristics is required, particularly the operational limitations, such as write speed, energy efficiency, and endurance, as well as size scaling limitations and contact material compatibility. For low temperature operation, minimization of dissipation is essential, so investigation of how the switching energy scales with device size is particularly important. The write (W) cycle of the CCM device was shown to be nonthermal, while the erase (E) cycle is at least partially thermal. (7) Intrinsic nonohmic behavior and dissipation at the contacts, (12) especially if energy barriers are formed as a result of interface chemistry, may limit the energy efficiency in small devices. (13) In this paper we investigate CCM scaling properties in the nonvolatile resistance switching region, which is particularly relevant for incorporation into cryocomputing environments where the device has potential applications. We investigate the electrical contact structure with high resolution electron microscopy, searching for possible interfacial layers that may limit device performance. We conclude by comparing the measured characteristics of CCM with other current and emerging memory devices.

The devices were nanofabricated by evaporating metal contacts on 1T-TaS2 single crystal flakes as can be seen on a scanning electron microscope (SEM) image in Figure 1a (see Methods in Suppporting Information). Switching characteristics were measured on many devices with very different gap sizes L (Figure 1b) between the Au electrodes, using a large range of “write” pulse lengths τW, from 16 ps to 600 ms. For short pulse switching, low-attenuation transmission line circuits were used in combination with picosecond digital electronics (see Methods in Supporting Information). We first present an analysis of the contact structure in Au/1T-TaS2 devices on Si/SiO2 substrates. A bright-field scanning transmission electron microscope (BF-STEM) image of a cross-section of two electrodes (one memory bit) and a zoom-in on the interface between the metal electrodes and 1T-TaS2 can be seen in Figure 1b and Figure 1c, respectively. The layered structure of the 1T-TaS2 crystal is clearly visible in Figure 1c. Part of the cross-section showing the entire structure of the device can be seen in Figure 1d. An energy-dispersive X-ray spectroscopy (EDS) analysis of the device’s interfaces is presented in Figure 1e, along the line scan marked with the red line in Figure 1d. Considering the overlap in the EDS spectrum for certain characteristic lines of elements (Ta M and Si K, Au M and S K), the individual layers of the fabricated CCM device can be identified (Figure 1e). Importantly, multiple EDS analyses (at ∼1 nm resolution) on different devices do not show any evidence of an oxide layer at the interface between the 1T-TaS2 crystal and the metal electrode, consistent with a previous report (13) and the voltage–current characteristics discussed below.

Figure 1

Figure 1. CCM device, EDS, and work function analysis. (a) SEM image of a typical CCM device used for measurements with transmission line contacts. (b) BF-STEM image of a cross-section of a fabricated CCM device (one memory bit). (c) Zoom-in to the interface between the metal electrode and 1T-TaS2 crystal. (d) Zoom-in to a part of the cross-section with the EDS line scan marked. (e) EDS analysis of the zoomed-in section, where individual layers are identified: Au (yellow), Pd (green), Ta (dark blue), S (light blue), Si (red), O (black), Ti (pink). (f) Top panel shows an AFM image of a part of the CCM device with the line scan for the KPFM measurement marked. Bottom panel shows KPFM measurement of the work functions for 1T-TaS2, SiO2, and Au electrodes along the line scan. (g) Schematic band diagram of the device based on the KPFM measurements. On the left is a band diagram of an interface between the Au electrode and the nearly commensurate (NC) metallic state at room temperature, and on the right is an interface between the Au electrode and the commensurate (C) charge density wave state at cryogenic temperature.

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To further ascertain the possible role of contacts in device functionality we measured the relative difference in work functions of the 1T-TaS2 and Au in a CCM device using a Kelvin probe force microscopy (KPFM). The upper panel in Figure 1f shows an atomic force microscope (AFM) image of a part of the CCM device, while the bottom panel in Figure 1f shows the KPFM potential difference as a function of the scanning position on the device. The scanning is performed across the 1T-TaS2 crystal, the Si/SiO2 substrate and the Au electrode, as indicated with the dashed line in Figure 1f, top panel. While the absolute value of was not calibrated, the relative difference of work functions is accurately determined,

in agreement with published values for = 5.5 ± 0.01 eV (single crystal) (14) and = 5.1–5.47 eV. (15) Judging from the KPFM measurement and the values from ref (15), it looks like our gold layer has facets with predominantly (100) or (110) orientation. The corresponding band diagrams for the room-temperature nearly commensurate (NC) metallic state and the low-temperature commensurate charge density wave (C-CDW) are shown in Figure 1g. Ideally electron injection from Au metal into the 1T-TaS2 CDW-gapped semiconductor with a gap eV  (16) takes place (Figure 1g), and the junction is expected to be ohmic. 1T-TaS2 reacts to charge injection by forming a conducting interface layer parallel to the interface. We thus do not expect a barrier to form at the interface with Au contacts due to carrier diffusion, which is consistent with the observed linear voltage–current curves (6) and the scaling behavior with device size and τW described in the following section.

While basic memristive switching of the CCM device at higher temperatures was discussed elsewhere, (6) a measurement that demonstrates millikelvin operation and switching from the high resistance (HI) state to low (LO) resistance state is illustrated by the R–T curve in Figure 2a, for a device with intercontact distance nm. The entire measurement cycle is shown starting from 280 K, cooling and switching at 350 mK by a single write (W) pulse, and heating back to 280 K, where the system reverts to its original state. Upon heating we observe characteristic steps, previously attributed to relaxation of domains. (7,17) The insert to Figure 2a shows the R–T curves on an expanded scale, showing a commonly observed hysteresis associated with the presence of additional phases (18,19) above 100 K.

Figure 2

Figure 2. Resistance switching and voltage–current characteristics of CCM devices. (a) Temperature dependence of the four-contact resistance R. Switching from RHI to RLO at 350 mK is caused by an electrical W pulse as indicated by the arrow. Heating above 90 K (red line) reverts the system to the RHI state. Inset to (a) shows the expanded scale of the R–T curve. (b, c) Pulsed measurements of the V–I curve for the W and E operations, respectively.

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A typical voltage–current (V–I) curve for a W cycle at 20 K is shown in Figure 2b for incrementally increasing current pulses through the CCM device with an intercontact distance nm (see insert to Figure 3b). In this measurement, the pulses were very long (), illustrating the versatility of the device (fast measurements are shown later). The V–I measurement allows us to accurately determine the switching threshold for both the write and erase processes. We observe a nonlinear V–I curve with an initial slope (dashed line) up to the mA. Above this current the voltage drops from 0.65 to 0.08 V and the device switches to a linear V–I relation with resistance (dashed line), remaining in this state indefinitely at this temperature. The V–I curve for W can be fit with

for (green line) and for (dashed line) in agreement with ref (6). To switch back to the pristine state, the erase (E) sequence is illustrated in Figure 2c where the current is ramped from to 0.4 mA. Initially we follow the RLO curve. Above a threshold mA the device switches to a high resistance state. As current is lowered to zero, the device remains in at low currents. The behavior is consistent with the previous V–I measurements with 10 μs pulses, (6) implying that it is not dependent on the pulse length over the range τW = 10–5–1 s.

Figure 3

Figure 3. Speed and energy efficiency scaling at 20 K. (a) Switching energy density εW as a function of pulse length τW. The inset shows the actual pulse shapes. Red line shows linear scaling, and blue line shows departure from linearity at short τW. The data point at 1.9 ps was taken from ref (21). (b) Switching threshold voltage VW as a function of distance between the electrodes L. The inset shows a device with variable L used in the measurement. Different symbol colors are for different physical devices. (c) Endurance measurement showing cycling between RLO and RHI for 106 cycles. Each pair of points represents 2 × 104 W/E cycles.

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Using 60 GHz Au transmission line contacts, fabricated on ∼50 nm thick 1T-TaS2 flakes on Si/SiO2 substrates (see Figure 1a, Methods in Supporting Information), we systematically study the W sequence of multiple CCM devices for different W pulse lengths τW ranging from 16 ps to 20 μs generated by electronic pulse generators in a single-pulse mode. For each pulse length, the pulse voltage was incrementally increased until the switching threshold was reached and recorded. Since the depends on sample geometry, in Figure 3a, we plot the switching energy density instead: ( is the crystal volume between electrodes, and is defined as the switching energy). The error bars include the systematic error of measurements and the estimated variation between different devices. The red line shows a linear relation , with . At shorter pulse lengths there is a departure from linearity denoted with the blue line, which most likely occurs due to an increase in transmission line losses in the GHz range. For the fastest device measured here (16 ps fwhm), the distance between contacts is and threshold W voltage , which gives a switching energy per bit of at 20 K. The resistance measured before and after switching is and , respectively. The resistance ratio is lower than the value observed with longer W pulses at low temperatures such as that shown in Figure 2a, which may be attributed to incomplete switching. However, both and resistance states have long-term stability at this temperature (20 K). To explore the switching capabilities of the CCM device in the ultrafast limit, an electro-optical setup that allows for ps pulse generation and detection was reported in ref (21), from which we include a data point = 1.9 ps in Figure 3a.

The scaling of the switching threshold voltage with intercontact distance is shown in Figure 3b. (A device with multiple L is shown in the inset.) Approximately linear scaling of is observed over nearly 2 orders of magnitude, 60 nm < L < 4 μm, that extrapolates to the origin, with a slight departure from linearity at the smallest . Considering the fact that the EDS analyses do not show any intermediate layer between Au and 1T-TaS2 and that the work function mismatch suggests ohmic contact behavior, we cannot directly attribute the observed small deviation from linearity to electrical contacts. One possible reason for the departure at small sizes may be related to the fact that the device size approaches the intrinsic 10–20 nm domain size measured in the low-resistance state of single crystals. (9,20) The efficiency of devices with feature sizes comparable to the domain size may be expected to decrease due to charge configuration pinning at the contacts.

In Figure 3c we show a typical endurance measurement at 20 K for a device with nm. Square pulses with and amplitude V are used for W, and asymmetric triangular E pulses with peak amplitude V and are used for erase (shown in the inset to Figure 3c). Each pair of corresponding and values shown by black and red dots, respectively, represents a measurement after 20 000 W/E cycles. We see that is remarkably stable over cycles, while initially increases slightly and later stabilizes after cycles when the measurement was terminated.

An immediate application of the device could be in cryocomputing, which has been heralded as an obvious solution to the overall challenge of reducing dissipation of computer systems. (5,22) In spite of huge research efforts and availability of superconducting circuits performing both single flux quantum (SFQ) and quantum information processing, (22) the absence of a fast low-energy cryogenic memory has prevented significant upscaling, (4,5) so CCM devices may offer a possible breakthrough. Considering the scaling limits of CCM devices, we find that while the measured value of is small compared with other current memory devices, the observed scaling laws suggest that can be reduced further by reducing and/or . Optimization of microwave electrical contacts seems to be essential in reducing the as well, since the losses in the transmission of GHz pulses are likely to be the cause for the departure from linear scaling in Figure 3a. Deviations from linearity might still be expected when approaches the intrinsic switching time . (23) These effects are likely to be important for device optimization, particulary for erase protocols. (7) Fundamentally, the measured is still significantly larger than the measured microscopic barrier EB = 15–21 meV ((2.4–3.4) × 10–6 fJ) obtained from thermal activation measurements. (17) This implies that in principle devices with much smaller can be built before reaching fundamental limits. It is also instructive to compare and with the lowest possible energy difference between two states that can be discerned thermodynamically on the basis of their entropy difference (the Brillouin–Landauer (BL) thermodynamic limit (24)). At K, fJ, so the presented CCM devices in Figure 3 are still far from this limit. For cryogenic memory applications, it is important that the CCM device could be driven by single flux quantum (SFQ) pulses. For a single SFQ pulse, the pulse energy may be estimated to = fJ, where we have assumed a typical critical current μA in the SFQ driver circuit. For a realistic CCM device with nm2 device area and a crystal thickness of 20 nm, the estimation from the linear fit in Figure 3a for switching with 2 ps (21) pulses gives fJ. Thus, on the basis of the presented scaling laws, CCM devices constructed using current fabrication techniques could be driven with single SFQ pulses, provided the coupling between the SFQ driver and the CCM microwave circuit is optimized.

In Figure 4 we compare operating parameters of the CCM with leading alternative technologies, including magnetic random-access memory (MRAM), phase change memory (PCM), and others. The smallest energy/bit values of 6 fJ/bit (25) and 8 fJ/bit (26) were reported for voltage-controlled magnetic anisotropy switching (MRAM) in Ta/CoFeB/MgO magnetic tunnel junctions (MTJ) and resistive switching in Ni/GeOx/HfON/TaN resistive random access memory (RRAM) devices, respectively (Figure 4b). The lowest theoretically predicted value for MTJs of a few   (27) is comparable to the , which was already experimentally achieved in CCM. This value is still much higher than the theoretical limit of fJ predicted for CCM. PCMs have both significantly higher switching energies (>600 fJ  (28)) and switching voltages (>1 V  (29,30)) than CCM, and even the smallest memristors such as 6 nm crossbar memristor arrays have a write power of , (31) which is higher than the predicted ∼0.1 for a much bigger CCM device ( nm3), estimated from the linear fit in Figure 3a. We note that our demonstration of a man-made nonvolatile electronic memory device uses less energy per bit (2.2 fJ/bit) than a human brain (∼10 fJ/synapse) and potentially much less than artificial synapses. (32) The CCM’s advantage is that it is >9 orders of magnitude faster.

Figure 4

Figure 4. Measured switching energy EW and speed of leading memory devices: (a) switching energy in correlation with device area; (b) switching times τW plotted against switching energy. References: PCM, (28,29) RRAM, (26,33−35) STT-RAM, (36−38) MRAM, (25,39) nMem, (40,41) JJ-CMOS memory, (42) OST-RAM, (43) Mott memory, (44) SRAM, (45−47) and DRAM. (47)

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Picosecond switching speeds of CCMs are similar to those reported by photomagnetic recording. (48) However, the switching energy density per bit is significantly smaller for CCM: (0.3 J/cm3 for CCM (21) vs 6 J/cm3 for photomagnetic recording), with the added advantage of two-contact electrical W/E and read (R) operations and the possibility of a very high packing density. For CCMs the current size limit is 10–20 nm, but for photomagnetic recording the size is limited by optical wavelengths used for W/E/R (hundreds of nm). Nanowire memory (nMem) (40,41) based on superconductive loops and nanowire cryotrons, Josephson magnetic random access memory (JMRAM), (49) superconducting quantum interference device (SQUID) memory, (50) and hybrid Josephson complementary metal oxide semiconductor (JJ-CMOS) memory (42,51,52) are all very promising solutions for a cryogenic memory. However, they are hard to scale down to the 10–20 nm regime and require additional driving periphery (4,53) (nMem, JMRAM and SQUID memory) or require voltage amplification for proper operation (4) (JJ-CMOS memory), which introduces additional dissipation into the circuits.

Thus, with presently demonstrated scalability (feature size, 60 nm to 4 μm; pulse length, 16 ps to 600 ms; voltage, 0.3–10 V) and with a wide operating temperature range (350 mK to 190 K), the CCM devices appear to be very versatile in comparison. The operating temperature range could be extended to higher T by appropriate choice of substrate. (17) So far, no other electronically ordered material has been found to exhibit significant metastability and thus 1T-TaS2 currently is the only material for CCM application. The device variability is small, as seen from the data on multiple devices shown in the scaling plots. Importantly for applications, thin films of 1T-TaS2 can be grown by various means (54−56) promising technological flexibility. For interfacing present CCM devices with single flux quantum devices, which is an obvious target application, nanocryotrons (nTrons) have been demonstrated to be a match in terms of output voltage, speed, and impedance. (57,58) However, nTrons could introduce additional design complexity and dissipation due to higher bias currents, (51) so direct driving by SFQ pulses might be preferable.

In comparison to complementary metal oxide semiconductor (CMOS) devices (42,51,52,59) and nanowire memories, (40,41) the CCM concept potentially offers advantages in terms of scaling, size, speed, energy efficiency, and operational simplicity. Compared with other fast memory, such as photomagnetic storage, (48) CCMs are more energy efficient and offer much higher data packing densities. The disadvantage is low-temperature operation, but considering its primary virtues are speed and energy efficiency, the target applications are in the cryocomputing environment. The presently measured energy efficiency (2.2 fJ/bit) is a consequence of very short write pulses needed, allowed by the inherent switching mechanism. Thus, the values shown here are limited by device size and transmission characteristics of the high-speed microwave circuit, not the intrinsic mechanism.

We conclude that while 1T-TaS2 appears to be unique in exhibiting combined set of properties useful for CCM operation, multilayer structures may introduce additional functionality that may result in improved performance and extended temperature range of operation. The additional degrees of freedom arising from interlayer interactions and proximity coupling (60) in 2D heterostructures may be expected to offer new possibilities for new CCM devices beyond the currently available materials.

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The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.nanolett.2c01116.

  • Description of materials and fabrication methods; description of DC and fast electrical measurement (PDF)

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  • Corresponding Author
    • Anze Mraz - Complex Matter Department F7, Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia;  Faculty of Electrical Engineering, University of Ljubljana, Tržaška cesta 25, 1000 Ljubljana, Slovenia;  Orcidhttps://orcid.org/0000-0002-8030-2628;  Email: [email protected]
  • Authors
    • Rok Venturini - Complex Matter Department F7, Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia;  Faculty of Mathematics and Physics, University of Ljubljana, Jadranska cesta 19, 1000 Ljubljana, Slovenia
    • Damjan Svetin - Complex Matter Department F7, Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia;  CENN Nanocenter, Jamova cesta 39, 1000 Ljubljana, Slovenia
    • Vitomir Sever - Complex Matter Department F7, Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia
    • Ian Aleksander Mihailovic - Complex Matter Department F7, Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia
    • Igor Vaskivskyi - Complex Matter Department F7, Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia
    • Bojan Ambrozic - CENN Nanocenter, Jamova cesta 39, 1000 Ljubljana, Slovenia
    • Goran Dražić - Jozef Stefan International Postgraduate School, Jamova cesta 39, 1000 Ljubljana, Slovenia;  Department of Materials Chemistry, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia;  Orcidhttps://orcid.org/0000-0001-7809-8050
    • Maria D’Antuono - Dipartimento di Fisica “Ettore Pancini”, Università di Napoli Federico II, Monte S. Angelo via Cinthia, 80126 Napoli, Italy;  CNR-SPIN, Complesso Monte Sant’Angelo, Via Cinthia, 80126 Napoli, Italy
    • Daniela Stornaiuolo - CNR-SPIN, Complesso Monte Sant’Angelo, Via Cinthia, 80126 Napoli, Italy;  Dipartimento di Fisica “Ettore Pancini”, Università di Napoli Federico II, Monte S. Angelo via Cinthia, 80126 Napoli, Italy
    • Francesco Tafuri - Dipartimento di Fisica “Ettore Pancini”, Università di Napoli Federico II, Monte S. Angelo via Cinthia, 80126 Napoli, Italy;  CNR-Istituto Nazionale di Ottica (CNR-INO), Largo Enrico Fermi 6, 50125 Florence, Italy
    • Dimitrios Kazazis - Paul Scherrer Institute, Forschungsstrasse 111, 5232 Villigen PSI, Switzerland;  Orcidhttps://orcid.org/0000-0002-2124-2813
    • Jan Ravnik - Paul Scherrer Institute, Forschungsstrasse 111, 5232 Villigen PSI, Switzerland
    • Yasin Ekinci - Paul Scherrer Institute, Forschungsstrasse 111, 5232 Villigen PSI, Switzerland
    • Dragan Mihailovic - Complex Matter Department F7, Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia;  CENN Nanocenter, Jamova cesta 39, 1000 Ljubljana, Slovenia;  Faculty of Mathematics and Physics, University of Ljubljana, Jadranska cesta 19, 1000 Ljubljana, Slovenia;  Jozef Stefan International Postgraduate School, Jamova cesta 39, 1000 Ljubljana, Slovenia
  • Author Contributions

    A.M., R.V., I.A.M., V.S., and I.V. performed electrical measurements experiments. A.M., D.Sv., D.K., J.R., and Y.E. fabricated the devices. M.D., D.St., and F.T. performed the 350 mK switching experiments. B.A. prepared the lamella for STEM analysis. G.D. performed STEM analysis. A.M., D.Sv., and D.M. devised the experiments. D.M. and A.M. wrote the paper.

  • Notes
    The authors declare no competing financial interest.

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This project has received funding from the EU-H2020 research and innovation program under Grant Agreement 654360, NFFA-Europe, having benefited from the access provided by Paul Scherrer Institute in Villigen, Switzerland within the framework of the NFFA-Europe Transnational Access Activity. We acknowledge the help of L. Cindro from F9 at JSI on contact bonding. We thank the support from the Slovenian Research Agency (Grant P1-0040; Grant PR-08972 to A.M., Grant PR-10496 to R.V., Grant PR-06158 to A.K., Grant PR-07589 to J.R., Grant I0-0005 to D.S., Grant J2-3041 to G.D.), Slovene Ministry of Education, Science and Sport (Grant C3330-19-952005, Raziskovalci-2.1-IJS-952005), ERC AdG (Grant GA320602, TRAJECTORY), and ERC PoC (Grant GA767176, Umem4QC). We thank the CENN Nanocenter for the use of AFM, FIB, and DaLI. This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Grant Agreement No 701647, PSI-FELLOW-II-3i. F.T. has been supported by the Project SQUAD-Programma STAR PLUS 2020.

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This article references 60 other publications.

  1. 1
    Holmes, D. S.; Kadin, A. M.; Johnson, M. W. Superconducting Computing in Large-Scale Hybrid Systems. Computer 2015, 48, 34– 42,  DOI: 10.1109/MC.2015.375
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  2. 2
    Soloviev, I. I. Beyond Moore’s technologies: operation principles of a superconductor alternative. Beilstein J. Nanotechnol. 2017, 8, 2689– 2710,  DOI: 10.3762/bjnano.8.269
    [Crossref], [PubMed], [CAS], Google Scholar
    2
    Beyond Moore's technologies: operation principles of a superconductor alternative
    Soloviev Igor I; Klenov Nikolay V; Bakurskiy Sergey V; Kupriyanov Mikhail Yu; Soloviev Igor I; Klenov Nikolay V; Klenov Nikolay V; Kupriyanov Mikhail Yu; Sidorenko Anatoli S; Gudkov Alexander L; Sidorenko Anatoli S
    Beilstein journal of nanotechnology (2017), 8 (), 2689-2710 ISSN:2190-4286.
    The predictions of Moore's law are considered by experts to be valid until 2020 giving rise to "post-Moore's" technologies afterwards. Energy efficiency is one of the major challenges in high-performance computing that should be answered. Superconductor digital technology is a promising post-Moore's alternative for the development of supercomputers. In this paper, we consider operation principles of an energy-efficient superconductor logic and memory circuits with a short retrospective review of their evolution. We analyze their shortcomings in respect to computer circuits design. Possible ways of further research are outlined.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC1MvislGlug%253D%253D&md5=b21202b0c2dbd4c4c5d7d3c97c3b5178
  3. 3
    Janod, E. Resistive Switching in Mott Insulators and Correlated Systems. Adv. Funct. Mater. 2015, 25, 6287– 6305,  DOI: 10.1002/adfm.201500823
    [Crossref], [CAS], Google Scholar
    3
    Resistive Switching in Mott Insulators and Correlated Systems
    Janod, Etienne; Tranchant, Julien; Corraze, Benoit; Querre, Madec; Stoliar, Pablo; Rozenberg, Marcelo; Cren, Tristan; Roditchev, Dimitri; Phuoc, Vinh Ta; Besland, Marie-Paule; Cario, Laurent
    Advanced Functional Materials (2015), 25 (40), 6287-6305CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)
    Resistive random access memories (ReRAM) form an emerging type of nonvolatile memories, based on an elec. driven resistive switching (RS) of an active material. This Feature Article focuses on a broad class of ReRAM where the active material is a Mott insulator or a correlated system. These materials can indeed undergo various insulator-to-metal transitions (IMT) in response to external perturbations such as electronic doping or temp. These IMT explain most of resistive switching obsd. in correlated insulators as, for example, the Joule heating induced RS in VO2. The main part of this Feature Article is dedicated to a new mechanism of resistive switching recently unveiled in canonical Mott insulators such as (V1-xCrx)2O3, NiS2-xSex and AM4Q8 (A = Ga, Ge; M = V, Nb, Ta, Mo; Q = S, Se, Te). In these narrow gap Mott insulators, an electronic avalanche breakdown induces a resistive switching, 1st volatile above a threshold elec. field of a few kV/cm and then nonvolatile at higher field. The low resistance state is related to the creation of granular conductive filaments, which, in the nonvolatile case, can be erased by Joule heating. ReRAM devices based on this new type of out of equil. Mott insulator-to-metal transition display promising performances.
    >> More from SciFinder ®
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  4. 4
    Tafuri, F., Ed. Fundamentals and Frontiers of the Josephson Effect; Springer Series in Materials Science, Vol. 286; Springer Nature, 2019; pp 632– 648.
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  5. 5
    Holmes, D. S.; Ripple, A. L.; Manheimer, M. A. Energy-Efficient Superconducting Computing─Power Budgets and Requirements. IEEE Trans. Appl. Supercond. 2013, 23, 1701610– 1701610,  DOI: 10.1109/TASC.2013.2244634
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  6. 6
    Vaskivskyi, I. Fast electronic resistance switching involving hidden charge density wave states. Nat. Commun. 2016, 7, 11442,  DOI: 10.1038/ncomms11442
    [Crossref], [PubMed], [CAS], Google Scholar
    6
    Fast electronic resistance switching involving hidden charge density wave states
    Vaskivskyi, I.; Mihailovic, I. A.; Brazovskii, S.; Gospodaric, J.; Mertelj, T.; Svetin, D.; Sutar, P.; Mihailovic, D.
    Nature Communications (2016), 7 (), 11442CODEN: NCAOBW; ISSN:2041-1723. (Nature Publishing Group)
    The functionality of computer memory elements is currently based on multi-stability, driven either by locally manipulating the d. of electrons in transistors or by switching magnetic or ferroelec. order. Another possibility is switching between metallic and insulating phases by the motion of ions, but their speed is limited by slow nucleation and inhomogeneous percolative growth. Here we demonstrate fast resistance switching in a charge d. wave system caused by pulsed current injection. As a charge pulse travels through the material, it converts a commensurately ordered polaronic Mott insulating state in 1T-TaS2 to a metastable electronic state with textured domain walls, accompanied with a conversion of polarons to band states, and concurrent rapid switching from an insulator to a metal. The large resistance change, high switching speed (30 ps) and ultralow energy per bit opens the way to new concepts in non-volatile memory devices manipulating all-electronic states.
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  7. 7
    Mihailovic, D. Ultrafast non-thermal and thermal switching in charge configuration memory devices based on 1T-TaS2. Appl. Phys. Lett. 2021, 119, 013106,  DOI: 10.1063/5.0052311
    [Crossref], [CAS], Google Scholar
    7
    Ultrafast non-thermal and thermal switching in charge configuration memory devices based on 1T-TaS2
    Mihailovic, D.; Svetin, D.; Vaskivskyi, I.; Venturini, R.; Lipovsek, B.; Mraz, A.
    Applied Physics Letters (2021), 119 (1), 013106CODEN: APPLAB; ISSN:0003-6951. (American Institute of Physics)
    Charge configuration memory (CCM) device operation is based on the controllable reconfiguration of electronic domains in a charge-d.-wave material. Since the dominant effect involves the manipulation of electrons rather than atoms, the devices can display sub-picosecond switching speed and ultralow, few femtojoule switching energy. The mechanisms involved in switching between domain states of different elec. resistances are highly non-trivial and involve trapping non-equil. charges within topol. protected domain states. Here, we discuss the underlying physics that are deemed essential for the operation of CCM devices, focusing on the unusual asymmetry between non-thermal "write" processes and thermal "erase" processes from the point of view of the mechanism in relation to the thermal dynamics. (c) 2021 American Institute of Physics.
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  8. 8
    Stojchevska, L. Ultrafast Switching to a Stable Hidden Quantum State in an Electronic Crystal. Science 2014, 344, 177– 180,  DOI: 10.1126/science.1241591
    [Crossref], [PubMed], [CAS], Google Scholar
    8
    Ultrafast Switching to a Stable Hidden Quantum State in an Electronic Crystal
    Stojchevska, L.; Vaskivskyi, I.; Mertelj, T.; Kusar, P.; Svetin, D.; Brazovskii, S.; Mihailovic, D.
    Science (Washington, DC, United States) (2014), 344 (6180), 177-180CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)
    Hidden states of matter may be created if a system out of equil. follows a trajectory to a state that is inaccessible or does not exist under normal equil. conditions. The authors found such a hidden (H) electronic state in a layered dichalcogenide crystal of 1T-TaS2 (the trigonal phase of tantalum disulfide) reached as a result of a quench caused by a single 35-fs laser pulse. In comparison to other states of the system, the H state exhibits a large drop of elec. resistance, strongly modified single-particle and collective-mode spectra, and a marked change of optical reflectivity. The H state is stable until a laser pulse, elec. current, or thermal erase procedure is applied, causing it to revert to the thermodn. ground state.
    >> More from SciFinder ®
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  9. 9
    Gerasimenko, Y. A.; Karpov, P.; Vaskivskyi, I.; Brazovskii, S.; Mihailovic, D. Intertwined chiral charge orders and topological stabilization of the light-induced state of a prototypical transition metal dichalcogenide. npj Quantum Mater. 2019, 4, 32,  DOI: 10.1038/s41535-019-0172-1
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  10. 10
    Ritschel, T. Orbital textures and charge density waves in transition metal dichalcogenides. Nat. Phys. 2015, 11, 328– 331,  DOI: 10.1038/nphys3267
    [Crossref], [CAS], Google Scholar
    10
    Orbital textures and charge density waves in transition metal dichalcogenides
    Ritschel, T.; Trinckauf, J.; Koepernik, K.; Buechner, B.; Zimmermann, M. v.; Berger, H.; Joe, Y. I.; Abbamonte, P.; Geck, J.
    Nature Physics (2015), 11 (4), 328-331CODEN: NPAHAX; ISSN:1745-2473. (Nature Publishing Group)
    Low-dimensional electron systems, as realized in layered materials, often tend to spontaneously break the symmetry of the underlying nuclear lattice by forming so-called d. waves; a state of matter that at present attracts enormous attention. Here we reveal a remarkable and surprising feature of charge d. waves, namely their intimate relation to orbital order. For the prototypical material 1T-TaS2 we not only show that the charge d. wave within the two-dimensional TaS2 layers involves previously unidentified orbital textures of great complexity. We also demonstrate that two metastable stackings of the orbitally ordered layers allow manipulation of salient features of the electronic structure. Indeed, these orbital effects provide a route to switch 1T-TaS2 nanostructures from metallic to semiconducting with technol. pertinent gaps of the order of 200 meV. This new type of orbitronics is esp. relevant for the ongoing development of novel, miniaturized and ultrafast devices based on layered transition metal dichalcogenides.
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  11. 11
    Stahl, Q. Collapse of layer dimerization in the photo-induced hidden state of 1T-TaS2. Nat. Commun. 2020, 11, 1247,  DOI: 10.1038/s41467-020-15079-1
    [Crossref], [PubMed], [CAS], Google Scholar
    11
    Collapse of layer dimerization in the photo-induced hidden state of 1T-TaS2
    Stahl, Quirin; Kusch, Maximilian; Heinsch, Florian; Garbarino, Gaston; Kretzschmar, Norman; Hanff, Kerstin; Rossnagel, Kai; Geck, Jochen; Ritschel, Tobias
    Nature Communications (2020), 11 (1), 1247CODEN: NCAOBW; ISSN:2041-1723. (Nature Research)
    Photo-induced switching between collective quantum states of matter is a fascinating rising field with exciting opportunities for novel technologies. Presently, very intensively studied examples in this regard are nanometer-thick single crystals of the layered material 1T-TaS2, where picosecond laser pulses can trigger a fully reversible insulator-to-metal transition (IMT). This IMT is believed to be connected to the switching between metastable collective quantum states, but the microscopic nature of this so-called hidden quantum state remained largely elusive up to now. Here, we characterize the hidden quantum state of 1T-TaS2 by means of state-of-the-art x-ray diffraction and show that the laser-driven IMT involves a marked rearrangement of the charge and orbital order in the direction perpendicular to the TaS2-layers. More specifically, we identify the collapse of interlayer MO dimers as a key mechanism for this non-thermal collective transition between two truly long-range ordered electronic crystals.
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  12. 12
    Zhu, X.; Li, A. J.; Stewart, G. R.; Hebard, A. F. Detection of charge density wave phase transitions at 1T-TaS2/GaAs interfaces. Appl. Phys. Lett. 2017, 110, 181603,  DOI: 10.1063/1.4982964
    [Crossref], [CAS], Google Scholar
    12
    Detection of charge density wave phase transitions at 1T-TaS2/GaAs interfaces
    Zhu, Xiaochen; Li, Ang J.; Stewart, G. R.; Hebard, Arthur F.
    Applied Physics Letters (2017), 110 (18), 181603/1-181603/5CODEN: APPLAB; ISSN:0003-6951. (American Institute of Physics)
    The transition metal dichalcogenide 1T-TaS2 is well known to harbor a rich variety of charge d. wave (CDW) distortions which are correlated with underlying lattice atom modulations. The long range CDW phases extend throughout the whole crystal and terminate with charge displacements at the crystal boundaries. Here, we report on the transport properties and capacitance characteristics of the interface between freshly exfoliated flakes of 1T-TaS2 in intimate van der Waals contact with n-type GaAs substrates. The extd. barrier parameters (ideality, barrier height, and built-in potential) experience pronounced changes across the Mott-CDW transition in the 1T-TaS2. The CDW-induced changes in barrier properties are well described by a bond polarization model which upon decreasing temp. gives rise to an increased potential drop across the interfacial region due to the localization of carriers and a decreased dielec. const. (c) 2017 American Institute of Physics.
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  13. 13
    Tsen, A. W. Structure and control of charge density waves in two-dimensional 1T-TaS2. Proc. Natl. Acad. Sci. U. S. A. 2015, 112, 15054– 15059,  DOI: 10.1073/pnas.1512092112
    [Crossref], [PubMed], [CAS], Google Scholar
    13
    Structure and control of charge density waves in two-dimensional 1T-TaS2
    Tsen, Adam W.; Hovden, Robert; Wang, Dennis; Kim, Young Duck; Okamoto, Junichi; Spoth, Katherine A.; Liu, Yu; Lu, Wenjian; Sun, Yuping; Hone, James C.; Kourkoutis, Lena F.; Kim, Philip; Pasupathy, Abhay N.
    Proceedings of the National Academy of Sciences of the United States of America (2015), 112 (49), 15054-15059CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)
    The layered transition metal dichalcogenides host a rich collection of charge d. wave phases in which both the conduction electrons and the at. structure display translational symmetry breaking. Manipulating these complex states by purely electronic methods has been a long-sought scientific and technol. goal. Here, we show how this can be achieved in 1T-TaS2 in the 2D limit. We first demonstrate that the intrinsic properties of atomically thin flakes are preserved by encapsulation with hexagonal boron nitride in inert atm. We use this facile assembly method together with transmission electron microscopy and transport measurements to probe the nature of the 2D state and show that its conductance is dominated by discommensurations. The discommensuration structure can be precisely tuned in few-layer samples by an in-plane elec. current, allowing continuous elec. control over the discommensuration-melting transition in 2D.
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  14. 14
    Perfetti, L. Femtosecond dynamics of electronic states in the Mott insulator 1T-TaS2 by time resolved photoelectron spectroscopy. New J. Phys. 2008, 10, 053019,  DOI: 10.1088/1367-2630/10/5/053019
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  15. 15
    Michaelson, H. B. The work function of the elements and its periodicity. J. Appl. Phys. 1977, 48, 4729– 4733,  DOI: 10.1063/1.323539
    [Crossref], [CAS], Google Scholar
    15
    The work function of the elements and its periodicity
    Michaelson, Herbert B.
    Journal of Applied Physics (1977), 48 (11), 4729-33CODEN: JAPIAU; ISSN:0021-8979.
    A review with 63 refs. is compiled based on a literature search for the period 1969-1976.
    >> More from SciFinder ®
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  16. 16
    Cho, D.; Cho, Y.-H.; Cheong, S.-W.; Kim, K.-S.; Yeom, H. W. Interplay of electron-electron and electron-phonon interactions in the low-temperature phase of 1 T – TaS 2. Phys. Rev. B 2015, 92, 085132,  DOI: 10.1103/PhysRevB.92.085132
    [Crossref], [CAS], Google Scholar
    16
    Interplay of electron-electron and electron-phonon interactions in the low-temperature phase of 1T-TaS2
    Cho, Doohee; Cho, Yong-Heum; Cheong, Sang-Wook; Kim, Ki-Seok; Yeom, Han Woong
    Physical Review B: Condensed Matter and Materials Physics (2015), 92 (8), 085132/1-085132/5CODEN: PRBMDO; ISSN:1098-0121. (American Physical Society)
    We investigate the interplay of the electron-electron and electron-phonon interactions in the electronic structure of an exotic insulating state in the layered dichalcogenide 1T-TaS2, where the charge-d.-wave (CDW) order coexists with a Mott correlation gap. Scanning tunneling microscopy and spectroscopy measurements with high spatial and energy resoln. det. unambiguously the CDW and the Mott gap as 0.20-0.24 eV and 0.32 eV, resp., through the real space electron phases measured across the multiply formed energy gaps. An unusual local redn. of the Mott gap is obsd. on the defect site, which indicates the renormalization of the on-site Coulomb interaction by the electron-phonon coupling as predicted by the Hubbard-Holstein model. The Mott-gap renormalization provides insight into the disorder-induced quasimetallic phases of 1T-TaS2.
    >> More from SciFinder ®
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  17. 17
    Vaskivskyi, I. Controlling the metal-to-insulator relaxation of the metastable hidden quantum state in 1T-TaS 2. Sci. Adv. 2015, 1, e1500168  DOI: 10.1126/sciadv.1500168
    [Crossref], [PubMed], [CAS], Google Scholar
    17
    Controlling the metal-to-insulator relaxation of the metastable hidden quantum state in 1T-TaS2
    Vaskivskyi, Igor; Gospodaric, Jan; Brazovskii, Serguei; Svetin, Damjan; Sutar, Petra; Goreshnik, Evgeny; Mihailovic, Ian A.; Mertelj, Tomaz; Mihailovic, Dragan
    Science Advances (2015), 1 (6), e1500168/1-e1500168/6CODEN: SACDAF; ISSN:2375-2548. (American Association for the Advancement of Science)
    Controllable switching between metastable macroscopic quantum states under nonequil. conditions induced either by light or with an external elec. field is rapidly becoming of great fundamental interest. We investigate the relaxation properties of a "hidden" (H) charge d. wave (CDW) state in thin single crystals of the layered dichalcogenide 1T-TaS2, which can be reached by either a single 35-fs optical laser pulse or an ∼30-ps elec. pulse. From measurements of the temp. dependence of the resistivity under different excitation conditions, we find that the metallic H state relaxes to the insulating Mott ground state through a sequence of intermediate metastable states via discrete jumps over a "Devil's staircase." In between the discrete steps, an underlying glassy relaxation process is obsd., which arises because of reciprocal-space commensurability frustration between the CDW and the underlying lattice. We show that the metastable state relaxation rate may be externally stabilized by substrate strain, thus opening the way to the design of nonvolatile ultrafast high-temp. memory devices based on switching between CDW states with large intrinsic differences in elec. resistance.
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  18. 18
    Tanda, S.; Sambongi, T.; Tani, T.; Tanaka, S. X-Ray Study of Charge Density Wave Structure in 1T-TaS2. J. Phys. Soc. Jpn. 1984, 53, 476– 479,  DOI: 10.1143/JPSJ.53.476
    [Crossref], [CAS], Google Scholar
    18
    X-ray study of charge density wave structure in 1T-tantalum disulfide
    Tanda, Satoshi; Sambongi, Takashi; Tani, Toshiro; Tanaka, Shoji
    Journal of the Physical Society of Japan (1984), 53 (2), 476-9CODEN: JUPSAU; ISSN:0031-9015.
    Positions of satellite reflections in charge-d. wave (CDW) phases of IT-TaS2 were measured by using x-ray diffraction. In the commensurate (C-) phase, stacking of CDW layers is considerably disordered. On heating from the C-phase there appears a new incommensurate triclinic structure at ≤280 K, where anomalies have been obsd. in various properties.
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  19. 19
    Wang, Y. D. Band insulator to Mott insulator transition in 1T-TaS2. Nat. Commun. 2020, 11, 4215,  DOI: 10.1038/s41467-020-18040-4
    [Crossref], [PubMed], [CAS], Google Scholar
    19
    Band insulator to Mott insulator transition in 1T-TaS2
    Wang, Y. D.; Yao, W. L.; Xin, Z. M.; Han, T. T.; Wang, Z. G.; Chen, L.; Cai, C.; Li, Yuan; Zhang, Y.
    Nature Communications (2020), 11 (1), 4215CODEN: NCAOBW; ISSN:2041-1723. (Nature Research)
    1T-TaS2 undergoes successive phase transitions upon cooling and eventually enters an insulating state of mysterious origin. Some consider this state to be a band insulator with interlayer stacking order, yet others attribute it to mott physics that support a quantum spin liq. state. Here, we det. the electronic and structural properties of 1T-TaS2 using angle-resolved photoemission spectroscopy and X-ray diffraction. At low temps., the 2π/2c-periodic band dispersion, along with half-integer-indexed diffraction peaks along the c axis, unambiguously indicates that the ground state of 1T-TaS2 is a band insulator with interlayer dimerization. Upon heating, however, the system undergoes a transition into a Mott insulating state, which only exists in a narrow temp. window. Our results refute the idea of searching for quantum magnetism in 1T-TaS2 only at low temps., and highlight the competition between on-site Coulomb repulsion and interlayer hopping as a crucial aspect for understanding the material's electronic properties.
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  20. 20
    Cho, D. Nanoscale manipulation of the Mott insulating state coupled to charge order in 1T-TaS2. Nat. Commun. 2016, 7, 10453,  DOI: 10.1038/ncomms10453
    [Crossref], [PubMed], [CAS], Google Scholar
    20
    Nanoscale manipulation of the Mott insulating state coupled to charge order in 1T-TaS2
    Cho, Doohee; Cheon, Sangmo; Kim, Ki-Seok; Lee, Sung-Hoon; Cho, Yong-Heum; Cheong, Sang-Wook; Yeom, Han Woong
    Nature Communications (2016), 7 (), 10453CODEN: NCAOBW; ISSN:2041-1723. (Nature Publishing Group)
    The controllability over strongly correlated electronic states promises unique electronic devices. A recent example is an optically induced ultrafast switching device based on the transition between the correlated Mott insulating state and a metallic state of a transition metal dichalcogenide 1T-TaS2. However, the electronic switching has been challenging and the nature of the transition has been veiled. Here we demonstrate the nanoscale electronic manipulation of the Mott state of 1T-TaS2. The voltage pulse from a scanning tunnelling microscope switches the insulating phase locally into a metallic phase with irregularly textured domain walls in the charge d. wave order inherent to this Mott state. The metallic state is revealed as a correlated phase, which is induced by the moderate redn. of electron correlation due to the charge d. wave decoherence.
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  21. 21
    Venturini, R. Ultra-Efficient Resistance Switching between Charge Ordered Phases in 1T-TaS2 with a Single Picosecond Electrical Pulse. arXiv 2022, 2202.13831
    Google Scholar
    There is no corresponding record for this reference.
  22. 22
    Anders, S. European roadmap on superconductive electronics – status and perspectives. Phys. C Supercond. 2010, 470, 2079– 2126,  DOI: 10.1016/j.physc.2010.07.005
    [Crossref], [CAS], Google Scholar
    22
    European roadmap on superconductive electronics - status and perspectives
    Anders, S.; Blamire, M. G.; Buchholz, F.-Im.; Crete, D.-G.; Cristiano, R.; Febvre, P.; Fritzsch, L.; Herr, A.; Il'ichev, E.; Kohlmann, J.; Kunert, J.; Meyer, H.-G.; Niemeyer, J.; Ortlepp, T.; Rogalla, H.; Schurig, T.; Siegel, M.; Stolz, R.; Tarte, E.; ter Brake, H. J. M.; Toepfer, H.; Villegier, J.-C.; Zagoskin, A. M.; Zorin, A. B.
    Physica C: Superconductivity and Its Applications (Amsterdam, Netherlands) (2010), 470 (23-24), 2079-2126CODEN: PHYCE6; ISSN:0921-4534. (Elsevier B.V.)
    A review. For 4 decades semiconductor electronics has followed Moore's law: with each generation of integration the circuit features became smaller, more complex and faster. This development is now reaching a wall so that smaller is no longer any faster. The clock rate has satd. at about 3-5 GHz and the parallel processor approach will soon reach its limit. The prime reason for the limitation the semiconductor electronics experiences is not the switching speed of the individual transistor, but its power dissipation and thus heat. Digital superconductive electronics is a circuit- and device-technol. that is inherently faster at much less power dissipation than semiconductor electronics. It makes use of superconductors and Josephson junctions as circuit elements, which can provide extremely fast digital devices in a frequency range, dependent on the material, of hundreds of GHz: for example a flip-flop has been demonstrated that operated at 750 GHz. This digital technique is scalable and follows similar design rules as semiconductor devices. Its very low power dissipation of only 0.1 μW per gate at 100 GHz opens the possibility of three-dimensional integration. Circuits like microprocessors and analog-to-digital converters for com. and military applications have been demonstrated. In contrast to semiconductor circuits, the operation of superconducting circuits is based on naturally standardized digital pulses the area of which is exactly the flux quantum Φ0. The flux quantum is also the natural quantization unit for digital-to-analog and analog-to-digital converters. The latter application is so precise, that it is being used as voltage std. and that the phys. unit Volt' is defined by means of this std. Apart from its outstanding features for digital electronics, superconductive electronics provides also the most sensitive sensor for magnetic fields: the Superconducting Quantum Interference Device (SQUID). Amongst many other applications SQUIDs are used as sensors for magnetic heart and brain signals in medical applications, as sensor for geol. surveying and food-processing and for non-destructive testing. As amplifiers of elec. signals, SQUIDs can nearly reach the theor. limit given by Quantum Mechanics. A further important field of application is the detection of very weak signals by transition-edge' bolometers, superconducting nanowire single-photon detectors, and superconductive tunnel junctions. Their application as radiation detectors in a wide frequency range, from microwaves to X-rays is now std. The very low losses of superconductors have led to com. microwave filter designs that are now widely used in the USA in base stations for cellular phones and in military communication applications. The no. of demonstrated applications is continuously increasing and there is no area in professional electronics, in which superconductive electronics cannot be applied and surpasses the performance of classical devices. Superconductive electronics has to be cooled to very low temps. Whereas this was a bottleneck in the past, cooling techniques have made a huge step forward in recent years: very compact systems with high reliability and a wide range of cooling power are available com., from microcoolers of match-box size with milli-Watt cooling power to high-reliability coolers of many Watts of cooling power for satellite applications. Superconductive electronics will not replace semiconductor electronics and similar room-temp. techniques in std. applications, but for those applications which require very high speed, low-power consumption, extreme sensitivity or extremely high precision, superconductive electronics is superior to all other available techniques. To strengthen the European competitiveness in superconductor electronics research projects have to be set-up in the following field:-Ultra-sensitive sensing and imaging. Quantum measurement instrumentation. Advanced analog-to-digital converters. Superconductive electronics technol.
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  23. 23
    Ravnik, J.; Vaskivskyi, I.; Mertelj, T.; Mihailovic, D. Real-time observation of the coherent transition to a metastable emergent state in 1T–TaS2. Phys. Rev. B 2018, 97, 075304,  DOI: 10.1103/PhysRevB.97.075304
    [Crossref], [CAS], Google Scholar
    23
    Real-time observation of the coherent transition to a metastable emergent state in 1T-TaS2
    Ravnik, Jan; Vaskivskyi, Igor; Mertelj, Tomaz; Mihailovic, Dragan
    Physical Review B (2018), 97 (7), 075304CODEN: PRBHB7; ISSN:2469-9969. (American Physical Society)
    The transition to a hidden metastable state in 1T-TaS2 is investigated in real time using coherent time-resolved femtosecond spectroscopy. Relying on spectral differences between phonon modes in the equil. states and in the metastable state, and temp.-tuning the metastable state lifetime, we perform stroboscopic measurements of the electronic response and switching of coherent oscillation frequency through the transition. Very fast coherent switching of the collective-mode frequency is obsd. (∼400fs), comparable to the electronic time scale ∼300fs. A slower, 4.7-ps process is attributed to lattice relaxation. The observations are described well by a fast electronic band structure transformation into the metastable state, consistent with a topol. transition.
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  24. 24
    Landauer, R. Irreversibility and Heat Generation in the Computing Process. IBM journal 1961, 5, 183,  DOI: 10.1147/rd.53.0183
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  25. 25
    Grezes, C. Ultra-low switching energy and scaling in electric-field-controlled nanoscale magnetic tunnel junctions with high resistance-area product. Appl. Phys. Lett. 2016, 108, 012403,  DOI: 10.1063/1.4939446
    [Crossref], [CAS], Google Scholar
    25
    Ultra-low switching energy and scaling in electric-field-controlled nanoscale magnetic tunnel junctions with high resistance-area product
    Grezes, C.; Ebrahimi, F.; Alzate, J. G.; Cai, X.; Katine, J. A.; Langer, J.; Ocker, B.; Khalili Amiri, P.; Wang, K. L.
    Applied Physics Letters (2016), 108 (1), 012403/1-012403/5CODEN: APPLAB; ISSN:0003-6951. (American Institute of Physics)
    The authors reported elec.-field-induced switching with write energies down to 6 fJ/bit for switching times of 0.5 ns, in nanoscale perpendicular magnetic tunnel junctions (MTJs) with high resistance-area product and diams. down to 50 nm. The ultra-low switching energy is made possible by a thick MgO barrier that ensures negligible spin-transfer torque contributions, along with a redn. of the Ohmic dissipation. The authors found that the switching voltage and time are insensitive to the junction diam. for high-resistance MTJs, a result accounted for by a macrospin model of purely voltage-induced switching. The measured performance enables integration with same-size CMOS transistors in compact memory and logic integrated circuits. (c) 2016 American Institute of Physics.
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  26. 26
    Cheng, C. H.; Chin, A.; Yeh, F. S. Ultralow Switching Energy Ni/GeOx/HfON/TaN RRAM. IEEE Electron Device Lett. 2011, 32, 366– 368,  DOI: 10.1109/LED.2010.2095820
    [Crossref], [CAS], Google Scholar
    26
    Ultralow switching energy Ni/GeOx/HfON/TaN RRAM
    Cheng, C. H.; Chin, Albert; Yeh, F. S.
    IEEE Electron Device Letters (2011), 32 (3), 366-368CODEN: EDLEDZ; ISSN:0741-3106. (Institute of Electrical and Electronics Engineers)
    Using stacked covalent-bond-dielec. GeOx on metal-oxynitride HfON, the Ni/GeOx/HfON/TaN resistive random access memory (RRAM) showed ultralow set power of 0.3 μW (0.1 μA at 3 V), reset power of 0.6 nW (-0.3 nA at -1.8 V), fast 20-ns switching time, ultralow 8-fJ switching energy (4-V overstress), and excellent 106 cycling endurance. Such excellent performance was reached by using hopping conduction with neg. temp. coeff. (TC) rather than the pos. TC in metal-oxide RRAM.
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  27. 27
    Wang, L. Voltage-Controlled Magnetic Tunnel Junctions for Processing-In-Memory Implementation. IEEE Electron Device Lett. 2018, 39, 440– 443,  DOI: 10.1109/LED.2018.2791510
    [Crossref], [CAS], Google Scholar
    27
    Voltage-controlled magnetic tunnel junctions for processing-in-memory implementation
    Wang, Lezhi; Kang, Wang; Ebrahimi, Farbod; Li, Xiang; Huang, Yangqi; Zhao, Chao; Wang, Kang L.; Zhao, Weisheng
    IEEE Electron Device Letters (2018), 39 (3), 440-443CODEN: EDLEDZ; ISSN:1558-0563. (Institute of Electrical and Electronics Engineers)
    The processing-in-memory (PIM) paradigm has been considered as a promising alternative to break the bottlenecks of conventional von-Neumann architecture by realizing the unity of data storage and processing in the same die. On the road toward implementing such an architecture, finding a novelmemory that can support both dense data storage and efficient logic processing is the crit. step. In this letter, we report a voltage-controlled magnetic tunnel junction (MTJ), which is a potential candidate for PIM implementation. Stateful Boolean logic functions can be realized with a single device through the memory-like write/read operations. The device was fabricated and characterized at room temp. Afterwards, typical Boolean logic operations, e.g., "OR", "AND", and "NXOR", were exptl. demonstrated with the fabricated MTJ device. The proposed approach opens up a new way for PIM implementation in spintronic memories.
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  28. 28
    Liu, B. Multi-level phase-change memory with ultralow power consumption and resistance drift. Sci. Bull. 2021, 66, 2217– 2224,  DOI: 10.1016/j.scib.2021.07.018
    [Crossref], [CAS], Google Scholar
    28
    Multi-level phase-change memory with ultralow power consumption and resistance drift
    Liu, Bin; Li, Kaiqi; Liu, Wanliang; Zhou, Jian; Wu, Liangcai; Song, Zhitang; Elliott, Stephen R.; Sun, Zhimei
    Science Bulletin (2021), 66 (21), 2217-2224CODEN: SBCUA5; ISSN:2095-9281. (Elsevier B.V.)
    By controlling the amorphous-to-cryst. relative vol., chalcogenide phase-change memory materials can provide multi-level data storage (MLS), which offers great potential for high-d. storage-class memory and neuro-inspired computing. However, this type of MLS system suffers from high power consumption and a severe time-dependent resistance increase ("drift") in the amorphous phase, which limits the no. of attainable storage levels. Here, we report a new type of MLS system in yttrium-doped antimony telluride, utilizing reversible multi-level phase transitions between three states, i.e., amorphous, metastable cubic and stable hexagonal cryst. phases, with ultralow power consumption (0.6-4.3 pJ) and ultralow resistance drift for the lower two states (power-law exponent < 0.007). The metastable cubic phase is stabilized by yttrium, while the evident reversible cubic-to-hexagonal transition is attributed to the sequential and directional migration of Sb atoms. Finally, the decreased heat dissipation of the material and the increase in crystallinity contribute to the overall high performance. This study opens a new way to achieve advanced multi-level phase-change memory without the need for complicated manufg. procedures or iterative programming operations.
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  29. 29
    Loke, D. Breaking the Speed Limits of Phase-Change Memory. Science 2012, 336, 1566– 1569,  DOI: 10.1126/science.1221561
    [Crossref], [PubMed], [CAS], Google Scholar
    29
    Breaking the Speed Limits of Phase-Change Memory
    Loke, D.; Lee, T. H.; Wang, W. J.; Shi, L. P.; Zhao, R.; Yeo, Y. C.; Chong, T. C.; Elliott, S. R.
    Science (Washington, DC, United States) (2012), 336 (6088), 1566-1569CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)
    Phase-change random-access memory (PCRAM) is one of the leading candidates for next-generation data-storage devices, but the trade-off between crystn. (writing) speed and amorphous-phase stability (data retention) presents a key challenge. We control the crystn. kinetics of a phase-change material by applying a const. low voltage via prestructural ordering (incubation) effects. A crystn. speed of 500 ps was achieved, as well as high-speed reversible switching using 500-ps pulses. Ab initio mol. dynamics simulations reveal the phase-change kinetics in PCRAM devices and the structural origin of the incubation-assisted increase in crystn. speed. This paves the way for achieving a broadly applicable memory device, capable of nonvolatile operations beyond gigahertz data-transfer rates.
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  30. 30
    Ding, K. Phase-change heterostructure enables ultralow noise and drift for memory operation. Science 2019, 366, 210– 215,  DOI: 10.1126/science.aay0291
    [Crossref], [PubMed], [CAS], Google Scholar
    30
    Phase-change heterostructure enables ultralow noise and drift for memory operation
    Ding, Keyuan; Wang, Jiangjing; Zhou, Yuxing; Tian, He; Lu, Lu; Mazzarello, Riccardo; Jia, Chunlin; Zhang, Wei; Rao, Feng; Ma, Evan
    Science (Washington, DC, United States) (2019), 366 (6462), 210-215CODEN: SCIEAS; ISSN:1095-9203. (American Association for the Advancement of Science)
    Artificial intelligence and other data-intensive applications have escalated the demand for data storage and processing. New computing devices, such as phase-change random access memory (PCRAM)-based neuro-inspired devices, are promising options for breaking the von Neumann barrier by unifying storage with computing in memory cells. However, current PCRAM devices have considerable noise and drift in elec. resistance that erodes the precision and consistency of these devices. We designed a phase-change heterostructure (PCH) that consists of alternately stacked phase-change and confinement nanolayers to suppress the noise and drift, allowing reliable iterative RESET and cumulative SET operations for high-performance neuro-inspired computing. Our PCH architecture is amenable to industrial prodn. as an intrinsic materials soln., without complex manufg. procedure or much increased fabrication cost.
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  31. 31
    Pi, S. Memristor crossbar arrays with 6-nm half-pitch and 2-nm critical dimension. Nat. Nanotechnol. 2019, 14, 35– 39,  DOI: 10.1038/s41565-018-0302-0
    [Crossref], [PubMed], [CAS], Google Scholar
    31
    Memristor crossbar arrays with 6-nm half-pitch and 2-nm critical dimension
    Pi, Shuang; Li, Can; Jiang, Hao; Xia, Weiwei; Xin, Huolin; Yang, J. Joshua; Xia, Qiangfei
    Nature Nanotechnology (2019), 14 (1), 35-39CODEN: NNAABX; ISSN:1748-3387. (Nature Research)
    The memristor1,2 is a promising building block for next-generation non-volatile memory3, artificial neural networks4-7 and bio-inspired computing systems8,9. Organizing small memristors into high-d. crossbar arrays is crit. to meet the ever-growing demands in high-capacity and low-energy consumption, but this is challenging because of difficulties in making highly ordered conductive nanoelectrodes. Carbon nanotubes, graphene nanoribbons and dopant nanowires have potential as electrodes for discrete nanodevices10-14, but unfortunately these are difficult to pack into ordered arrays. Transfer printing, on the other hand, is effective in generating dense electrode arrays15 but has yet to prove suitable for making fully random accessible crossbars. All the aforementioned electrodes have dramatically increased resistance at the nanoscale16-18, imposing a significant barrier to their adoption in operational circuits. Here we demonstrate memristor crossbar arrays with a 2-nm feature size and a single-layer d. up to 4.5 terabits per square inch, comparable to the information d. achieved using three-dimensional stacking in state-of-the-art 64-layer and multilevel 3D-NAND flash memory19. Memristors in the arrays switch with tens of nanoamperes elec. current with nonlinear behavior. The densely packed crossbar arrays of individually accessible, extremely small functional memristors provide a power-efficient soln. for information storage and processing.
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  32. 32
    Xu, W.; Min, S.-Y.; Hwang, H.; Lee, T.-W. Organic core-sheath nanowire artificial synapses with femtojoule energy consumption. Sci. Adv. 2016, 2, e1501326  DOI: 10.1126/sciadv.1501326
    [Crossref], [PubMed], [CAS], Google Scholar
    32
    Organic core-sheath nanowire artificial synapses with femtojoule energy consumption
    Xu, Wentao; Min, Sung-Yong; Hwang, Hyunsang; Lee, Tae-Woo
    Science Advances (2016), 2 (6), e1501326/1-e1501326/7CODEN: SACDAF; ISSN:2375-2548. (American Association for the Advancement of Science)
    Emulation of biol. synapses is an important step toward construction of large-scale brain-inspired electronics. Despite remarkable progress in emulating synaptic functions, current synaptic devices still consume energy that is orders of magnitude greater than do biol. synapses (∼10 fJ per synaptic event). Redn. of energy consumption of artificial synapses remains a difficult challenge. We report org. nanowire (ONW) synaptic transistors (STs) that emulate the important working principles of a biol. synapse. The ONWs emulate the morphol. of nerve fibers. With a core-sheath-structured ONW active channel and a well-confined 300-nm channel length obtained using ONW lithog., ∼1.23 fJ per synaptic event for individual ONW was attained, which rivals that of biol. synapses. The ONW STs provide a significant step toward realizing low-energy-consuming artificial intelligent electronics and open new approaches to assembling soft neuromorphic systems with nanometer feature size.
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  33. 33
    Havel, V.; Ultrafast switching in Ta2O5-based resistive memories. In 2016 IEEE Silicon Nanoelectronics Workshop (SNW) 82–83; IEEE, 2016;  DOI: 10.1109/SNW.2016.7577995 .
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  34. 34
    Torrezan, A. C.; Strachan, J. P.; Medeiros-Ribeiro, G.; Williams, R. S. Sub-nanosecond switching of a tantalum oxide memristor. Nanotechnology 2011, 22, 485203,  DOI: 10.1088/0957-4484/22/48/485203
    [Crossref], [PubMed], [CAS], Google Scholar
    34
    Sub-nanosecond switching of a tantalum oxide memristor
    Torrezan, Antonio C.; Strachan, John Paul; Medeiros-Ribeiro, Gilberto; Williams, R. Stanley
    Nanotechnology (2011), 22 (48), 485203/1-485203/7CODEN: NNOTER; ISSN:1361-6528. (Institute of Physics Publishing)
    We report sub-nanosecond switching of a metal-oxide-metal memristor utilizing a broadband 20 GHz exptl. setup developed to observe fast switching dynamics. Set and reset operations were successfully performed in the tantalum oxide memristor using pulses with durations of 105 and 120 ps, resp. Reproducibility of the sub-nanosecond switching was also confirmed as the device switched over consecutive cycles.
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  35. 35
    Lee, S.; Sohn, J.; Jiang, Z.; Chen, H.-Y.; Philip Wong, H.-S. Metal oxide-resistive memory using graphene-edge electrodes. Nat. Commun. 2015, 6, 8407,  DOI: 10.1038/ncomms9407
    [Crossref], [PubMed], [CAS], Google Scholar
    35
    Metal oxide-resistive memory using graphene-edge electrodes
    Lee Seunghyun; Sohn Joon; Jiang Zizhen; Chen Hong-Yu; Philip Wong H-S
    Nature communications (2015), 6 (), 8407 ISSN:.
    The emerging paradigm of 'abundant-data' computing requires real-time analytics on enormous quantities of data collected by a mushrooming network of sensors. Todays computing technology, however, cannot scale to satisfy such big data applications with the required throughput and energy efficiency. The next technology frontier will be monolithically integrated chips with three-dimensionally interleaved memory and logic for unprecedented data bandwidth with reduced energy consumption. In this work, we exploit the atomically thin nature of the graphene edge to assemble a resistive memory (∼ 3 ÅA thick) stacked in a vertical three-dimensional structure. We report some of the lowest power and energy consumption among the emerging non-volatile memories due to an extremely thin electrode with unique properties, low programming voltages, and low current. Circuit analysis of the three-dimensional architecture using experimentally measured device properties show higher storage potential for graphene devices compared that of metal based devices.
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  36. 36
    Ando, K. Spin-transfer torque magnetoresistive random-access memory technologies for normally off computing (invited). J. Appl. Phys. 2014, 115, 172607,  DOI: 10.1063/1.4869828
    [Crossref], [CAS], Google Scholar
    36
    Spin-transfer torque magnetoresistive random-access memory technologies for normally off computing (invited)
    Ando, K.; Fujita, S.; Ito, J.; Yuasa, S.; Suzuki, Y.; Nakatani, Y.; Miyazaki, T.; Yoda, H.
    Journal of Applied Physics (Melville, NY, United States) (2014), 115 (17), 172607/1-172607/6CODEN: JAPIAU; ISSN:0021-8979. (American Institute of Physics)
    Most parts of present computer systems are made of volatile devices, and the power to supply them to avoid information loss causes huge energy losses. We can eliminate this meaningless energy loss by utilizing the non-volatile function of advanced spin-transfer torque magnetoresistive random-access memory (STT-MRAM) technol. and create a new type of computer, i.e., normally off computers. Crit. tasks to achieve normally off computers are implementations of STT-MRAM technologies in the main memory and low-level cache memories. STT-MRAM technol. for applications to the main memory was successfully developed by perpendicular STT-MRAMs, and faster STT-MRAM technologies for applications to the cache memory are now being developed. The present status of STT-MRAMs and challenges that remain for normally off computers are discussed. (c) 2014 American Institute of Physics.
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  37. 37
    Jan, G.; Demonstration of Ultra-Low Voltage and Ultra Low Power STT-MRAM designed for compatibility with 0x node embedded LLC applications. In 2018 IEEE Symposium on VLSI Technology 65–66; IEEE, 2018.
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  38. 38
    Rehm, L. Sub-nanosecond switching in a cryogenic spin-torque spin-valve memory element with a dilute permalloy free layer. Appl. Phys. Lett. 2019, 114, 212402,  DOI: 10.1063/1.5094924
    [Crossref], [CAS], Google Scholar
    38
    Sub-nanosecond switching in a cryogenic spin-torque spin-valve memory element with a dilute permalloy free layer
    Rehm, L.; Sluka, V.; Rowlands, G. E.; Nguyen, M.-H.; Ohki, T. A.; Kent, A. D.
    Applied Physics Letters (2019), 114 (21), 212402/1-212402/4CODEN: APPLAB; ISSN:0003-6951. (American Institute of Physics)
    We present a study of pulsed current switching characteristics of spin-valve nanopillars with in-plane magnetized dil. permalloy and undiluted permalloy free layers in the ballistic regime at low temps. The dil. permalloy free layer device switches much faster: the characteristic switching time for a permalloy (Ni0.83Fe0.17) free layer device is 1.18 ns, while that for a dil. permalloy ([Ni0.83Fe0.17]0.6Cu0.4) free layer device is 0.475 ns. A ballistic macrospin model can capture the data trends with a reduced spin-torque asymmetry parameter, reduced spin polarization, and increased Gilbert damping for the dil. permalloy free layer relative to the permalloy devices. Our study demonstrates that reducing the magnetization of the free layer increases the switching speed while greatly reducing the switching energy and shows a promising route toward even lower power magnetic memory devices compatible with superconducting electronics. (c) 2019 American Institute of Physics.
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  39. 39
    Khalili Amiri, P. Electric-Field-Controlled Magnetoelectric RAM: Progress, Challenges, and Scaling. IEEE Trans. Magn. 2015, 51, 1– 7,  DOI: 10.1109/TMAG.2015.2443124
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  40. 40
    Zhao, Q.-Y. A compact superconducting nanowire memory element operated by nanowire cryotrons. Supercond. Sci. Technol. 2018, 31, 035009,  DOI: 10.1088/1361-6668/aaa820
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  41. 41
    McCaughan, A. N.; Toomey, E.; Schneider, M.; Berggren, K. K.; Nam, S. W. A kinetic-inductance-based superconducting memory element with shunting and sub-nanosecond write times. Supercond. Sci. Technol. 2019, 32, 015005,  DOI: 10.1088/1361-6668/aae50d
    [Crossref], [CAS], Google Scholar
    41
    A kinetic-inductance-based superconducting memory element with shunting and sub-nanosecond write times
    McCaughan, Adam N.; Toomey, Emily; Schneider, Michael; Berggren, Karl K.; Nam, Sae Woo
    Superconductor Science and Technology (2019), 32 (1), 015005/1-015005/6CODEN: SUSTEF; ISSN:0953-2048. (IOP Publishing Ltd.)
    We present a kinetic-inductance-based superconducting memory element with non-destructive readout, femtojoule read and write energies, both read and write shunts, which is writeable with pulses shorter than 400 ps. The element utilizes both a high-kinetic-inductance layer made from tungsten silicide as well as a low-kinetic-inductance layer made from niobium. By using tungsten silicide-which has a long (20 ns) thermal time const.-and measuring bit error rates from 10 MHz to 1 GHz, we were able to verify that the thin-film elements could be operated at a data rate at least as fast as the material thermal time const. with a bit error ratio less than 10-6. We also analyze the margins of the device, and outline the characteristics by which a more efficient device may be designed.
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  42. 42
    Konno, G.; Yamanashi, Y.; Yoshikawa, N. Fully Functional Operation of Low-Power 64-kb Josephson-CMOS Hybrid Memories. IEEE Trans. Appl. Supercond. 2017, 27, 1– 7,  DOI: 10.1109/TASC.2016.2646911
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  43. 43
    Krivorotov, I. N.; Ultrafast spin torque memory based on magnetic tunnel junctions with combined in-plane and perpendicular polarizers. In 70th Device Research Conference 211–212; IEEE, 2012.
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  44. 44
    Pickett, M. D.; Stanley Williams, R. Sub-100 fJ and sub-nanosecond thermally driven threshold switching in niobium oxide crosspoint nanodevices. Nanotechnology 2012, 23, 215202,  DOI: 10.1088/0957-4484/23/21/215202
    [Crossref], [PubMed], [CAS], Google Scholar
    44
    Sub-100 fJ and sub-nanosecond thermally driven threshold switching in niobium oxide crosspoint nanodevices
    Pickett, Matthew D.; Williams, R. Stanley
    Nanotechnology (2012), 23 (21), 215202/1-215202/9CODEN: NNOTER; ISSN:1361-6528. (Institute of Physics Publishing)
    We built and measured the dynamical current vs. time behavior of nanoscale niobium oxide crosspoint devices which exhibited threshold switching (current-controlled neg. differential resistance). The switching speeds of 110 × 110 nm2 devices were found to be ΔtON = 700 ps and ΔtOFF = 2.3 ns while the switching energies were of the order of 100 fJ. We derived a new dynamical model based on the Joule heating rate of a thermally driven insulator-to-metal phase transition that accurately reproduced the exptl. results, and employed the model to est. the switching time and energy scaling behavior of such devices down to the 10 nm scale. These results indicate that threshold switches could be of practical interest in hybrid CMOS nanoelectronic circuits.
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  45. 45
    Clerc, S.; A 0.32V, 55fJ per bit access energy, CMOS 65nm bit-interleaved SRAM with radiation Soft Error tolerance. In 2012 IEEE International Conference on IC Design & Technology 1–4; IEEE, 2012;  DOI: 10.1109/ICICDT.2012.6232860 .
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  46. 46
    Wang, K. L.; Alzate, J. G.; Khalili Amiri, P. Low-power non-volatile spintronic memory: STT-RAM and beyond. J. Phys. Appl. Phys. 2013, 46, 074003,  DOI: 10.1088/0022-3727/46/7/074003
    [Crossref], [CAS], Google Scholar
    46
    Low-power non-volatile spintronic memory: STT-RAM and beyond
    Wang, K. L.; Alzate, J. G.; Khalili Amiri, P.
    Journal of Physics D: Applied Physics (2013), 46 (7), 074003CODEN: JPAPBE; ISSN:0022-3727. (IOP Publishing Ltd.)
    The quest for novel low-dissipation devices is one of the most crit. for the future of semiconductor technol. and nano-systems. The development of a low-power, universal memory will enable a new paradigm of non-volatile computation. Here we consider STT-RAM as one of the emerging candidates for low-power non-volatile memory. We show different configurations for STT memory and demonstrate strategies to optimize key performance parameters such as switching current and energy. The energy and scaling limits of STT-RAM are discussed, leading us to argue that alternative writing mechanisms may be required to achieve ultralow power dissipation, a necessary condition for direct integration with CMOS at the gate level for non-volatile logic purposes. As an example, we discuss the use of the giant spin Hall effect as a possible alternative to induce magnetization reversal in magnetic tunnel junctions using pure spin currents. Further, we conc. on magnetoelec. effects, where elec. fields are used instead of spin-polarized currents to manipulate the nanomagnets, as another candidate soln. to address the challenges of energy efficiency and d. The possibility of an elec.-field-controlled magnetoelec. RAM as a promising candidate for ultralow-power non-volatile memory is discussed in the light of exptl. data demonstrating voltage-induced switching of the magnetization and reorientation of the magnetic easy axis by elec. fields in nanomagnets.
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  47. 47
    Dieny, B. Opportunities and challenges for spintronics in the microelectronics industry. Nat. Electron. 2020, 3, 446– 459,  DOI: 10.1038/s41928-020-0461-5
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  48. 48
    Stupakiewicz, A.; Szerenos, K.; Afanasiev, D.; Kirilyuk, A.; Kimel, A. V. Ultrafast nonthermal photo-magnetic recording in a transparent medium. Nature 2017, 542, 71– 74,  DOI: 10.1038/nature20807
    [Crossref], [PubMed], [CAS], Google Scholar
    48
    Ultrafast nonthermal photo-magnetic recording in a transparent medium
    Stupakiewicz, A.; Szerenos, K.; Afanasiev, D.; Kirilyuk, A.; Kimel, A. V.
    Nature (London, United Kingdom) (2017), 542 (7639), 71-74CODEN: NATUAS; ISSN:0028-0836. (Nature Publishing Group)
    Discovering ways to control the magnetic state of media with the lowest possible prodn. of heat and at the fastest possible speeds is important in the study of fundamental magnetism, with clear practical potential. In metals, it is possible to switch the magnetization between two stable states (and thus to record magnetic bits) using femtosecond circularly polarized laser pulses. However, the switching mechanisms in these materials are directly related to laser-induced heating close to the Curie temp. Although several possible routes for achieving all-optical switching in magnetic dielecs. have been discussed, no recording has hitherto been demonstrated. Here we describe ultrafast all-optical photo-magnetic recording in transparent films of the dielec. cobalt-substituted garnet. A single linearly polarized femtosecond laser pulse resonantly pumps specific d-d transitions in the cobalt ions, breaking the degeneracy between metastable magnetic states. By changing the polarization of the laser pulse, we deterministically steer the net magnetization in the garnet, thus writing '0' and '1' magnetic bits at will. This mechanism outperforms existing alternatives in terms of the speed of the write-read magnetic recording event (less than 20 ps) and the unprecedentedly low heat load (less than 6 J/cm3).
    >> More from SciFinder ®
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  49. 49
    Dayton, I. M. Experimental Demonstration of a Josephson Magnetic Memory Cell With a Programmable π-Junction. IEEE Magn. Lett. 2018, 9, 1– 5,  DOI: 10.1109/LMAG.2018.2801820
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  50. 50
    Takeshita, Y. High-Speed Memory Driven by SFQ Pulses Based on 0-π SQUID. IEEE Trans. Appl. Supercond. 2021, 31, 1– 6,  DOI: 10.1109/TASC.2021.3060351
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  51. 51
    Tanaka, M. Josephson-CMOS Hybrid Memory With Nanocryotrons. IEEE Trans. Appl. Supercond. 2017, 27, 1– 4,  DOI: 10.1109/TASC.2016.2646929
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  52. 52
    Van Duzer, T. 64-kb Hybrid Josephson-CMOS 4 K RAM With 400 ps Access Time and 12 mW Read Power. IEEE Trans. Appl. Supercond. 2013, 23, 1700504– 1700504,  DOI: 10.1109/TASC.2012.2230294
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  53. 53
    Tolpygo, S. K. Superconductor digital electronics: Scalability and energy efficiency issues (Review Article). Low Temp. Phys. 2016, 42, 361– 379,  DOI: 10.1063/1.4948618
    [Crossref], [CAS], Google Scholar
    53
    Superconductor digital electronics: Scalability and energy efficiency issues (Review Article)
    Tolpygo, Sergey K.
    Low Temperature Physics (2016), 42 (5), 361-379CODEN: LTPHEG; ISSN:1063-777X. (American Institute of Physics)
    Superconductor digital electronics using Josephson junctions as ultrafast switches and magnetic-flux encoding of information was proposed over 30 years ago as a sub-terahertz clock frequency alternative to semiconductor electronics based on complementary metal-oxide-semiconductor (CMOS) transistors. Recently, interest in developing superconductor electronics has been renewed due to a search for energy saving solns. in applications related to high-performance computing. The current state of superconductor electronics and fabrication processes are reviewed in order to evaluate whether this electronics is scalable to a very large scale integration (VLSI) required to achieve computation complexities comparable to CMOS processors. A fully planarized process at MIT Lincoln Lab., perhaps the most advanced process developed so far for superconductor electronics, is used as an example. The process has nine superconducting layers: eight Nb wiring layers with the min. feature size of 350 nm, and a thin superconducting layer for making compact high-kinetic-inductance bias inductors. All circuit layers are fully planarized using chem. mech. planarization (CMP) of SiO2 interlayer dielec. The phys. limitations imposed on the circuit d. by Josephson junctions, circuit inductors, shunt and bias resistors, etc., are discussed. Energy dissipation in superconducting circuits is also reviewed in order to est. whether this technol., which requires cryogenic refrigeration, can be energy efficient. Fabrication process development required for increasing the d. of superconductor digital circuits by a factor of ten and achieving densities above 107 Josephson junctions per cm2 is described. (c) 2016 American Institute of Physics.
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  54. 54
    Enomoto, H.; Kawano, T.; Kawaguchi, M.; Takano, Y.; Sekizawa, K. Van der Waals Growth of Thin TaS 2 on Layered Substrates by Chemical Vapor Transport Technique. Jpn. J. Appl. Phys. 2004, 43, L123– L126,  DOI: 10.1143/JJAP.43.L123
    [Crossref], [CAS], Google Scholar
    54
    Van der Waals growth of thin TaS2 on layered substrates by chemical vapor transport technique
    Enomoto, Hiroyuki; Kawano, Takanori; Kawaguchi, Masayuki; Takano, Yoshiki; Sekizawa, Kazuko
    Japanese Journal of Applied Physics, Part 2: Letters & Express Letters (2004), 43 (2A), L123-L126CODEN: JAPLD8 ISSN:. (Japan Society of Applied Physics)
    Thin TaS2 was prepd. by the van der Waals growth technique coupled with the chem. vapor transport technique using the I2 agent. Hexagonal B nitride (h-BN) and mica, which have layered crystal structures, were used as substrate materials. Thin TaS2 was grown on layered substrates sealed in a quartz ampul. A high-resoln. x-ray diffractometer with a four-crystal monochrometer revealed that very thin 2H-TaS2 film was grown on the surface of the Ag/BN substrate at 300°, where Ag was evapd. on the h-BN substrate surface prior to the film growth. As for the mica substrate, very thin 2H-TaS2 was grown on the substrates with and without Ag modification.
    >> More from SciFinder ®
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  55. 55
    Sanders, C. E. Crystalline and electronic structure of single-layer TaS 2. Phys. Rev. B 2016, 94, 081404,  DOI: 10.1103/PhysRevB.94.081404
    [Crossref], [CAS], Google Scholar
    55
    Crystalline and electronic structure of single-layer TaS2
    Sanders, Charlotte E.; Dendzik, Maciej; Ngankeu, Arlette S.; Eich, Andreas; Bruix, Albert; Bianchi, Marco; Miwa, Jill A.; Hammer, Bjoerk; Khajetoorians, Alexander A.; Hofmann, Philip
    Physical Review B (2016), 94 (8), 081404/1-081404/5CODEN: PRBHB7; ISSN:2469-9950. (American Physical Society)
    Single-layer TaS2 is epitaxially grown on Au(111) substrates. The resulting two-dimensional crystals adopt the 1H polymorph. The electronic structure is detd. by angle-resolved photoemission spectroscopy and found to be in excellent agreement with d. functional theory calcns. The single-layer TaS2 is found to be strongly n doped, with a carrier concn. of 0.3(1) extra electrons per unit cell. No superconducting or charge d. wave state is obsd. by scanning tunneling microscopy at temps. down to 4.7 K.
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  56. 56
    Wang, X. Chemical Growth of 1 T -TaS 2 Monolayer and Thin Films: Robust Charge Density Wave Transitions and High Bolometric Responsivity. Adv. Mater. 2018, 30, 1800074,  DOI: 10.1002/adma.201800074
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  57. 57
    Zhao, Q.-Y.; McCaughan, A. N.; Dane, A. E.; Berggren, K. K.; Ortlepp, T. A nanocryotron comparator can connect single-flux-quantum circuits to conventional electronics. Supercond. Sci. Technol. 2017, 30, 044002,  DOI: 10.1088/1361-6668/aa5f33
    [Crossref], [CAS], Google Scholar
    57
    A nanocryotron comparator can connect single-flux-quantum circuits to conventional electronics
    Zhao, Qing-Yuan; McCaughan, Adam N.; Dane, Andrew E.; Berggren, Karl K.; Ortlepp, Thomas
    Superconductor Science and Technology (2017), 30 (4), 044002/1-044002/7CODEN: SUSTEF; ISSN:0953-2048. (IOP Publishing Ltd.)
    Integration with conventional electronics offers a straightforward and economical approach to upgrading existing superconducting technologies, such as scaling up superconducting detectors into large arrays and combining single flux quantum (SFQ) digital circuits with semiconductor logic gates and memories. However, direct output signals from superconducting devices (e.g., Josephson junctions) are usually not compatible with the input requirements of conventional devices (e.g., transistors). Here, we demonstrate the use of a single three-terminal superconducting-nanowire device, called the nanocryotron (nTron), as a digital comparator to combine SFQ circuits with mature semiconductor circuits such as complementary metal oxide semiconductor (CMOS) circuits. Since SFQ circuits can digitize output signals from general superconducting devices and CMOS circuits can interface existing CMOS-compatible electronics, our results demonstrate the feasibility of a general architecture that uses an nTron as an interface to realize a 'super-hybrid' system consisting of superconducting detectors, superconducting quantum electronics, CMOS logic gates and memories, and other conventional electronics.
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  58. 58
    Mraz, A.; Kabanov, V. V.; Mihailovic, D. Nanocryotron-driven Charge Configuration Memory. arXiv 2022, 2203.14586
    Google Scholar
    There is no corresponding record for this reference.
  59. 59
    Mukhanov, O. A.; Kirichenko, A. F.; Filippov, T. V.; Sarwana, S. Hybrid Semiconductor-Superconductor Fast-Readout Memory for Digital RF Receivers. IEEE Trans. Appl. Supercond. 2011, 21, 797– 800,  DOI: 10.1109/TASC.2010.2089409
    [Crossref], [CAS], Google Scholar
    59
    Hybrid semiconductor-superconductor fast-readout memory for digital RF receivers
    Mukhanov, O. A.; Kirichenko, A. F.; Filippov, T. V.; Sarwana, S.
    IEEE Transactions on Applied Superconductivity (2011), 21 (3, Pt. 1), 797-800CODEN: ITASE9; ISSN:1051-8223. (Institute of Electrical and Electronics Engineers)
    Results of the development of a new type of a hybrid memory for superconducting Digital-RF receivers supporting 30 Gbps memory readout speed are presented. The main feature of this memory is a combination of a high capacity room-temp. memory and a high speed on-chip superconductive cache in order to provide digital waveform templates for Digital-RF signal processing. As a room-temp. high-capacity memory with fast readout, we selected Sympuls pattern generator BMG 30 G-64 M capable of producing a 30 Gbps serial data stream of programmable pattern of 67,108,864 bits. We designed, fabricated, and tested an on-chip cache which receives high-speed template serial data from the room temp. memory and converts it into a stream of 3-bit words of template of local oscillator (LO) for digital mixer. We integrated the memory with a 1 × 3-bit digital I/Q mixer (1-bit digitized RF stream multiplied by 3-bit digital LO).
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  60. 60
    Joshi, J. Charge density wave activated excitons in TiSe2–MoSe2 heterostructures. APL Mater. 2022, 10, 011103,  DOI: 10.1063/5.0067098
    [Crossref], [CAS], Google Scholar
    60
    Charge density wave activated excitons in TiSe2-MoSe2 heterostructures
    Joshi, Jaydeep; Scharf, Benedikt; Mazin, Igor; Krylyuk, Sergiy; Campbell, Daniel J.; Paglione, Johnpierre; Davydov, Albert; Zutic, Igor; Vora, Patrick M.
    APL Materials (2022), 10 (1), 011103CODEN: AMPADS; ISSN:2166-532X. (American Institute of Physics)
    Layered materials enable the assembly of a new class of heterostructures where lattice-matching is no longer a requirement. Interfaces in these heterostructures therefore become a fertile ground for unexplored physics as dissimilar phenomena can be coupled via proximity effects. In this article, we identify an unexpected photoluminescence (PL) peak when MoSe2 interacts with TiSe2. A series of temp.-dependent and spatially resolved PL measurements reveal that this peak is unique to the TiSe2-MoSe2 interface, is higher in energy compared to the neutral exciton, and exhibits exciton-like characteristics. The feature disappears at the TiSe2 charge d. wave transition, suggesting that the d. wave plays an important role in the formation of this new exciton. We present several plausible scenarios regarding the origin of this peak that individually capture some aspects of our observations but cannot fully explain this feature. These results therefore represent a fresh challenge for the theor. community and provide a fascinating way to engineer excitons through interactions with charge d. waves. (c) 2022 American Institute of Physics.
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Cited By

This article is cited by 2 publications.

  1. Nabamita Chakraborty, Joy Ghosh, Saswata Goswami, Avinash Shaw, Biswajit Das, Abhijit Mallik, Kalyan K. Chattopadhyay. Perforated Turbostratic Graphene As Active Layer in a Nonvolatile Resistive Switching Memory Device. ACS Applied Electronic Materials 2023, 5 (4) , 2131-2144. https://doi.org/10.1021/acsaelm.3c00037
  2. Tiantian Huang, Rui Zhang, Lepeng Zhang, Peiran Xu, Yunkai Shao, Wanli Yang, Zhimin Chen, Xin Chen, Ning Dai. Energy-adaptive resistive switching with controllable thresholds in insulator–metal transition. RSC Advances 2022, 12 (55) , 35579-35586. https://doi.org/10.1039/D2RA06866D
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  • Abstract

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    Figure 1

    Figure 1. CCM device, EDS, and work function analysis. (a) SEM image of a typical CCM device used for measurements with transmission line contacts. (b) BF-STEM image of a cross-section of a fabricated CCM device (one memory bit). (c) Zoom-in to the interface between the metal electrode and 1T-TaS2 crystal. (d) Zoom-in to a part of the cross-section with the EDS line scan marked. (e) EDS analysis of the zoomed-in section, where individual layers are identified: Au (yellow), Pd (green), Ta (dark blue), S (light blue), Si (red), O (black), Ti (pink). (f) Top panel shows an AFM image of a part of the CCM device with the line scan for the KPFM measurement marked. Bottom panel shows KPFM measurement of the work functions for 1T-TaS2, SiO2, and Au electrodes along the line scan. (g) Schematic band diagram of the device based on the KPFM measurements. On the left is a band diagram of an interface between the Au electrode and the nearly commensurate (NC) metallic state at room temperature, and on the right is an interface between the Au electrode and the commensurate (C) charge density wave state at cryogenic temperature.

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    Figure 2

    Figure 2. Resistance switching and voltage–current characteristics of CCM devices. (a) Temperature dependence of the four-contact resistance R. Switching from RHI to RLO at 350 mK is caused by an electrical W pulse as indicated by the arrow. Heating above 90 K (red line) reverts the system to the RHI state. Inset to (a) shows the expanded scale of the R–T curve. (b, c) Pulsed measurements of the V–I curve for the W and E operations, respectively.

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    Figure 3. Speed and energy efficiency scaling at 20 K. (a) Switching energy density εW as a function of pulse length τW. The inset shows the actual pulse shapes. Red line shows linear scaling, and blue line shows departure from linearity at short τW. The data point at 1.9 ps was taken from ref (21). (b) Switching threshold voltage VW as a function of distance between the electrodes L. The inset shows a device with variable L used in the measurement. Different symbol colors are for different physical devices. (c) Endurance measurement showing cycling between RLO and RHI for 106 cycles. Each pair of points represents 2 × 104 W/E cycles.

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    Figure 4. Measured switching energy EW and speed of leading memory devices: (a) switching energy in correlation with device area; (b) switching times τW plotted against switching energy. References: PCM, (28,29) RRAM, (26,33−35) STT-RAM, (36−38) MRAM, (25,39) nMem, (40,41) JJ-CMOS memory, (42) OST-RAM, (43) Mott memory, (44) SRAM, (45−47) and DRAM. (47)

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  • References

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    This article references 60 other publications.

    1. 1
      Holmes, D. S.; Kadin, A. M.; Johnson, M. W. Superconducting Computing in Large-Scale Hybrid Systems. Computer 2015, 48, 34– 42,  DOI: 10.1109/MC.2015.375
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    2. 2
      Soloviev, I. I. Beyond Moore’s technologies: operation principles of a superconductor alternative. Beilstein J. Nanotechnol. 2017, 8, 2689– 2710,  DOI: 10.3762/bjnano.8.269
      [Crossref], [PubMed], [CAS], Google Scholar
      2
      Beyond Moore's technologies: operation principles of a superconductor alternative
      Soloviev Igor I; Klenov Nikolay V; Bakurskiy Sergey V; Kupriyanov Mikhail Yu; Soloviev Igor I; Klenov Nikolay V; Klenov Nikolay V; Kupriyanov Mikhail Yu; Sidorenko Anatoli S; Gudkov Alexander L; Sidorenko Anatoli S
      Beilstein journal of nanotechnology (2017), 8 (), 2689-2710 ISSN:2190-4286.
      The predictions of Moore's law are considered by experts to be valid until 2020 giving rise to "post-Moore's" technologies afterwards. Energy efficiency is one of the major challenges in high-performance computing that should be answered. Superconductor digital technology is a promising post-Moore's alternative for the development of supercomputers. In this paper, we consider operation principles of an energy-efficient superconductor logic and memory circuits with a short retrospective review of their evolution. We analyze their shortcomings in respect to computer circuits design. Possible ways of further research are outlined.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC1MvislGlug%253D%253D&md5=b21202b0c2dbd4c4c5d7d3c97c3b5178
    3. 3
      Janod, E. Resistive Switching in Mott Insulators and Correlated Systems. Adv. Funct. Mater. 2015, 25, 6287– 6305,  DOI: 10.1002/adfm.201500823
      [Crossref], [CAS], Google Scholar
      3
      Resistive Switching in Mott Insulators and Correlated Systems
      Janod, Etienne; Tranchant, Julien; Corraze, Benoit; Querre, Madec; Stoliar, Pablo; Rozenberg, Marcelo; Cren, Tristan; Roditchev, Dimitri; Phuoc, Vinh Ta; Besland, Marie-Paule; Cario, Laurent
      Advanced Functional Materials (2015), 25 (40), 6287-6305CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)
      Resistive random access memories (ReRAM) form an emerging type of nonvolatile memories, based on an elec. driven resistive switching (RS) of an active material. This Feature Article focuses on a broad class of ReRAM where the active material is a Mott insulator or a correlated system. These materials can indeed undergo various insulator-to-metal transitions (IMT) in response to external perturbations such as electronic doping or temp. These IMT explain most of resistive switching obsd. in correlated insulators as, for example, the Joule heating induced RS in VO2. The main part of this Feature Article is dedicated to a new mechanism of resistive switching recently unveiled in canonical Mott insulators such as (V1-xCrx)2O3, NiS2-xSex and AM4Q8 (A = Ga, Ge; M = V, Nb, Ta, Mo; Q = S, Se, Te). In these narrow gap Mott insulators, an electronic avalanche breakdown induces a resistive switching, 1st volatile above a threshold elec. field of a few kV/cm and then nonvolatile at higher field. The low resistance state is related to the creation of granular conductive filaments, which, in the nonvolatile case, can be erased by Joule heating. ReRAM devices based on this new type of out of equil. Mott insulator-to-metal transition display promising performances.
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    4. 4
      Tafuri, F., Ed. Fundamentals and Frontiers of the Josephson Effect; Springer Series in Materials Science, Vol. 286; Springer Nature, 2019; pp 632– 648.
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    5. 5
      Holmes, D. S.; Ripple, A. L.; Manheimer, M. A. Energy-Efficient Superconducting Computing─Power Budgets and Requirements. IEEE Trans. Appl. Supercond. 2013, 23, 1701610– 1701610,  DOI: 10.1109/TASC.2013.2244634
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    6. 6
      Vaskivskyi, I. Fast electronic resistance switching involving hidden charge density wave states. Nat. Commun. 2016, 7, 11442,  DOI: 10.1038/ncomms11442
      [Crossref], [PubMed], [CAS], Google Scholar
      6
      Fast electronic resistance switching involving hidden charge density wave states
      Vaskivskyi, I.; Mihailovic, I. A.; Brazovskii, S.; Gospodaric, J.; Mertelj, T.; Svetin, D.; Sutar, P.; Mihailovic, D.
      Nature Communications (2016), 7 (), 11442CODEN: NCAOBW; ISSN:2041-1723. (Nature Publishing Group)
      The functionality of computer memory elements is currently based on multi-stability, driven either by locally manipulating the d. of electrons in transistors or by switching magnetic or ferroelec. order. Another possibility is switching between metallic and insulating phases by the motion of ions, but their speed is limited by slow nucleation and inhomogeneous percolative growth. Here we demonstrate fast resistance switching in a charge d. wave system caused by pulsed current injection. As a charge pulse travels through the material, it converts a commensurately ordered polaronic Mott insulating state in 1T-TaS2 to a metastable electronic state with textured domain walls, accompanied with a conversion of polarons to band states, and concurrent rapid switching from an insulator to a metal. The large resistance change, high switching speed (30 ps) and ultralow energy per bit opens the way to new concepts in non-volatile memory devices manipulating all-electronic states.
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    7. 7
      Mihailovic, D. Ultrafast non-thermal and thermal switching in charge configuration memory devices based on 1T-TaS2. Appl. Phys. Lett. 2021, 119, 013106,  DOI: 10.1063/5.0052311
      [Crossref], [CAS], Google Scholar
      7
      Ultrafast non-thermal and thermal switching in charge configuration memory devices based on 1T-TaS2
      Mihailovic, D.; Svetin, D.; Vaskivskyi, I.; Venturini, R.; Lipovsek, B.; Mraz, A.
      Applied Physics Letters (2021), 119 (1), 013106CODEN: APPLAB; ISSN:0003-6951. (American Institute of Physics)
      Charge configuration memory (CCM) device operation is based on the controllable reconfiguration of electronic domains in a charge-d.-wave material. Since the dominant effect involves the manipulation of electrons rather than atoms, the devices can display sub-picosecond switching speed and ultralow, few femtojoule switching energy. The mechanisms involved in switching between domain states of different elec. resistances are highly non-trivial and involve trapping non-equil. charges within topol. protected domain states. Here, we discuss the underlying physics that are deemed essential for the operation of CCM devices, focusing on the unusual asymmetry between non-thermal "write" processes and thermal "erase" processes from the point of view of the mechanism in relation to the thermal dynamics. (c) 2021 American Institute of Physics.
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    8. 8
      Stojchevska, L. Ultrafast Switching to a Stable Hidden Quantum State in an Electronic Crystal. Science 2014, 344, 177– 180,  DOI: 10.1126/science.1241591
      [Crossref], [PubMed], [CAS], Google Scholar
      8
      Ultrafast Switching to a Stable Hidden Quantum State in an Electronic Crystal
      Stojchevska, L.; Vaskivskyi, I.; Mertelj, T.; Kusar, P.; Svetin, D.; Brazovskii, S.; Mihailovic, D.
      Science (Washington, DC, United States) (2014), 344 (6180), 177-180CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)
      Hidden states of matter may be created if a system out of equil. follows a trajectory to a state that is inaccessible or does not exist under normal equil. conditions. The authors found such a hidden (H) electronic state in a layered dichalcogenide crystal of 1T-TaS2 (the trigonal phase of tantalum disulfide) reached as a result of a quench caused by a single 35-fs laser pulse. In comparison to other states of the system, the H state exhibits a large drop of elec. resistance, strongly modified single-particle and collective-mode spectra, and a marked change of optical reflectivity. The H state is stable until a laser pulse, elec. current, or thermal erase procedure is applied, causing it to revert to the thermodn. ground state.
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    9. 9
      Gerasimenko, Y. A.; Karpov, P.; Vaskivskyi, I.; Brazovskii, S.; Mihailovic, D. Intertwined chiral charge orders and topological stabilization of the light-induced state of a prototypical transition metal dichalcogenide. npj Quantum Mater. 2019, 4, 32,  DOI: 10.1038/s41535-019-0172-1
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    10. 10
      Ritschel, T. Orbital textures and charge density waves in transition metal dichalcogenides. Nat. Phys. 2015, 11, 328– 331,  DOI: 10.1038/nphys3267
      [Crossref], [CAS], Google Scholar
      10
      Orbital textures and charge density waves in transition metal dichalcogenides
      Ritschel, T.; Trinckauf, J.; Koepernik, K.; Buechner, B.; Zimmermann, M. v.; Berger, H.; Joe, Y. I.; Abbamonte, P.; Geck, J.
      Nature Physics (2015), 11 (4), 328-331CODEN: NPAHAX; ISSN:1745-2473. (Nature Publishing Group)
      Low-dimensional electron systems, as realized in layered materials, often tend to spontaneously break the symmetry of the underlying nuclear lattice by forming so-called d. waves; a state of matter that at present attracts enormous attention. Here we reveal a remarkable and surprising feature of charge d. waves, namely their intimate relation to orbital order. For the prototypical material 1T-TaS2 we not only show that the charge d. wave within the two-dimensional TaS2 layers involves previously unidentified orbital textures of great complexity. We also demonstrate that two metastable stackings of the orbitally ordered layers allow manipulation of salient features of the electronic structure. Indeed, these orbital effects provide a route to switch 1T-TaS2 nanostructures from metallic to semiconducting with technol. pertinent gaps of the order of 200 meV. This new type of orbitronics is esp. relevant for the ongoing development of novel, miniaturized and ultrafast devices based on layered transition metal dichalcogenides.
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    11. 11
      Stahl, Q. Collapse of layer dimerization in the photo-induced hidden state of 1T-TaS2. Nat. Commun. 2020, 11, 1247,  DOI: 10.1038/s41467-020-15079-1
      [Crossref], [PubMed], [CAS], Google Scholar
      11
      Collapse of layer dimerization in the photo-induced hidden state of 1T-TaS2
      Stahl, Quirin; Kusch, Maximilian; Heinsch, Florian; Garbarino, Gaston; Kretzschmar, Norman; Hanff, Kerstin; Rossnagel, Kai; Geck, Jochen; Ritschel, Tobias
      Nature Communications (2020), 11 (1), 1247CODEN: NCAOBW; ISSN:2041-1723. (Nature Research)
      Photo-induced switching between collective quantum states of matter is a fascinating rising field with exciting opportunities for novel technologies. Presently, very intensively studied examples in this regard are nanometer-thick single crystals of the layered material 1T-TaS2, where picosecond laser pulses can trigger a fully reversible insulator-to-metal transition (IMT). This IMT is believed to be connected to the switching between metastable collective quantum states, but the microscopic nature of this so-called hidden quantum state remained largely elusive up to now. Here, we characterize the hidden quantum state of 1T-TaS2 by means of state-of-the-art x-ray diffraction and show that the laser-driven IMT involves a marked rearrangement of the charge and orbital order in the direction perpendicular to the TaS2-layers. More specifically, we identify the collapse of interlayer MO dimers as a key mechanism for this non-thermal collective transition between two truly long-range ordered electronic crystals.
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    12. 12
      Zhu, X.; Li, A. J.; Stewart, G. R.; Hebard, A. F. Detection of charge density wave phase transitions at 1T-TaS2/GaAs interfaces. Appl. Phys. Lett. 2017, 110, 181603,  DOI: 10.1063/1.4982964
      [Crossref], [CAS], Google Scholar
      12
      Detection of charge density wave phase transitions at 1T-TaS2/GaAs interfaces
      Zhu, Xiaochen; Li, Ang J.; Stewart, G. R.; Hebard, Arthur F.
      Applied Physics Letters (2017), 110 (18), 181603/1-181603/5CODEN: APPLAB; ISSN:0003-6951. (American Institute of Physics)
      The transition metal dichalcogenide 1T-TaS2 is well known to harbor a rich variety of charge d. wave (CDW) distortions which are correlated with underlying lattice atom modulations. The long range CDW phases extend throughout the whole crystal and terminate with charge displacements at the crystal boundaries. Here, we report on the transport properties and capacitance characteristics of the interface between freshly exfoliated flakes of 1T-TaS2 in intimate van der Waals contact with n-type GaAs substrates. The extd. barrier parameters (ideality, barrier height, and built-in potential) experience pronounced changes across the Mott-CDW transition in the 1T-TaS2. The CDW-induced changes in barrier properties are well described by a bond polarization model which upon decreasing temp. gives rise to an increased potential drop across the interfacial region due to the localization of carriers and a decreased dielec. const. (c) 2017 American Institute of Physics.
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    13. 13
      Tsen, A. W. Structure and control of charge density waves in two-dimensional 1T-TaS2. Proc. Natl. Acad. Sci. U. S. A. 2015, 112, 15054– 15059,  DOI: 10.1073/pnas.1512092112
      [Crossref], [PubMed], [CAS], Google Scholar
      13
      Structure and control of charge density waves in two-dimensional 1T-TaS2
      Tsen, Adam W.; Hovden, Robert; Wang, Dennis; Kim, Young Duck; Okamoto, Junichi; Spoth, Katherine A.; Liu, Yu; Lu, Wenjian; Sun, Yuping; Hone, James C.; Kourkoutis, Lena F.; Kim, Philip; Pasupathy, Abhay N.
      Proceedings of the National Academy of Sciences of the United States of America (2015), 112 (49), 15054-15059CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)
      The layered transition metal dichalcogenides host a rich collection of charge d. wave phases in which both the conduction electrons and the at. structure display translational symmetry breaking. Manipulating these complex states by purely electronic methods has been a long-sought scientific and technol. goal. Here, we show how this can be achieved in 1T-TaS2 in the 2D limit. We first demonstrate that the intrinsic properties of atomically thin flakes are preserved by encapsulation with hexagonal boron nitride in inert atm. We use this facile assembly method together with transmission electron microscopy and transport measurements to probe the nature of the 2D state and show that its conductance is dominated by discommensurations. The discommensuration structure can be precisely tuned in few-layer samples by an in-plane elec. current, allowing continuous elec. control over the discommensuration-melting transition in 2D.
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    14. 14
      Perfetti, L. Femtosecond dynamics of electronic states in the Mott insulator 1T-TaS2 by time resolved photoelectron spectroscopy. New J. Phys. 2008, 10, 053019,  DOI: 10.1088/1367-2630/10/5/053019
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    15. 15
      Michaelson, H. B. The work function of the elements and its periodicity. J. Appl. Phys. 1977, 48, 4729– 4733,  DOI: 10.1063/1.323539
      [Crossref], [CAS], Google Scholar
      15
      The work function of the elements and its periodicity
      Michaelson, Herbert B.
      Journal of Applied Physics (1977), 48 (11), 4729-33CODEN: JAPIAU; ISSN:0021-8979.
      A review with 63 refs. is compiled based on a literature search for the period 1969-1976.
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    16. 16
      Cho, D.; Cho, Y.-H.; Cheong, S.-W.; Kim, K.-S.; Yeom, H. W. Interplay of electron-electron and electron-phonon interactions in the low-temperature phase of 1 T – TaS 2. Phys. Rev. B 2015, 92, 085132,  DOI: 10.1103/PhysRevB.92.085132
      [Crossref], [CAS], Google Scholar
      16
      Interplay of electron-electron and electron-phonon interactions in the low-temperature phase of 1T-TaS2
      Cho, Doohee; Cho, Yong-Heum; Cheong, Sang-Wook; Kim, Ki-Seok; Yeom, Han Woong
      Physical Review B: Condensed Matter and Materials Physics (2015), 92 (8), 085132/1-085132/5CODEN: PRBMDO; ISSN:1098-0121. (American Physical Society)
      We investigate the interplay of the electron-electron and electron-phonon interactions in the electronic structure of an exotic insulating state in the layered dichalcogenide 1T-TaS2, where the charge-d.-wave (CDW) order coexists with a Mott correlation gap. Scanning tunneling microscopy and spectroscopy measurements with high spatial and energy resoln. det. unambiguously the CDW and the Mott gap as 0.20-0.24 eV and 0.32 eV, resp., through the real space electron phases measured across the multiply formed energy gaps. An unusual local redn. of the Mott gap is obsd. on the defect site, which indicates the renormalization of the on-site Coulomb interaction by the electron-phonon coupling as predicted by the Hubbard-Holstein model. The Mott-gap renormalization provides insight into the disorder-induced quasimetallic phases of 1T-TaS2.
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    17. 17
      Vaskivskyi, I. Controlling the metal-to-insulator relaxation of the metastable hidden quantum state in 1T-TaS 2. Sci. Adv. 2015, 1, e1500168  DOI: 10.1126/sciadv.1500168
      [Crossref], [PubMed], [CAS], Google Scholar
      17
      Controlling the metal-to-insulator relaxation of the metastable hidden quantum state in 1T-TaS2
      Vaskivskyi, Igor; Gospodaric, Jan; Brazovskii, Serguei; Svetin, Damjan; Sutar, Petra; Goreshnik, Evgeny; Mihailovic, Ian A.; Mertelj, Tomaz; Mihailovic, Dragan
      Science Advances (2015), 1 (6), e1500168/1-e1500168/6CODEN: SACDAF; ISSN:2375-2548. (American Association for the Advancement of Science)
      Controllable switching between metastable macroscopic quantum states under nonequil. conditions induced either by light or with an external elec. field is rapidly becoming of great fundamental interest. We investigate the relaxation properties of a "hidden" (H) charge d. wave (CDW) state in thin single crystals of the layered dichalcogenide 1T-TaS2, which can be reached by either a single 35-fs optical laser pulse or an ∼30-ps elec. pulse. From measurements of the temp. dependence of the resistivity under different excitation conditions, we find that the metallic H state relaxes to the insulating Mott ground state through a sequence of intermediate metastable states via discrete jumps over a "Devil's staircase." In between the discrete steps, an underlying glassy relaxation process is obsd., which arises because of reciprocal-space commensurability frustration between the CDW and the underlying lattice. We show that the metastable state relaxation rate may be externally stabilized by substrate strain, thus opening the way to the design of nonvolatile ultrafast high-temp. memory devices based on switching between CDW states with large intrinsic differences in elec. resistance.
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    18. 18
      Tanda, S.; Sambongi, T.; Tani, T.; Tanaka, S. X-Ray Study of Charge Density Wave Structure in 1T-TaS2. J. Phys. Soc. Jpn. 1984, 53, 476– 479,  DOI: 10.1143/JPSJ.53.476
      [Crossref], [CAS], Google Scholar
      18
      X-ray study of charge density wave structure in 1T-tantalum disulfide
      Tanda, Satoshi; Sambongi, Takashi; Tani, Toshiro; Tanaka, Shoji
      Journal of the Physical Society of Japan (1984), 53 (2), 476-9CODEN: JUPSAU; ISSN:0031-9015.
      Positions of satellite reflections in charge-d. wave (CDW) phases of IT-TaS2 were measured by using x-ray diffraction. In the commensurate (C-) phase, stacking of CDW layers is considerably disordered. On heating from the C-phase there appears a new incommensurate triclinic structure at ≤280 K, where anomalies have been obsd. in various properties.
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    19. 19
      Wang, Y. D. Band insulator to Mott insulator transition in 1T-TaS2. Nat. Commun. 2020, 11, 4215,  DOI: 10.1038/s41467-020-18040-4
      [Crossref], [PubMed], [CAS], Google Scholar
      19
      Band insulator to Mott insulator transition in 1T-TaS2
      Wang, Y. D.; Yao, W. L.; Xin, Z. M.; Han, T. T.; Wang, Z. G.; Chen, L.; Cai, C.; Li, Yuan; Zhang, Y.
      Nature Communications (2020), 11 (1), 4215CODEN: NCAOBW; ISSN:2041-1723. (Nature Research)
      1T-TaS2 undergoes successive phase transitions upon cooling and eventually enters an insulating state of mysterious origin. Some consider this state to be a band insulator with interlayer stacking order, yet others attribute it to mott physics that support a quantum spin liq. state. Here, we det. the electronic and structural properties of 1T-TaS2 using angle-resolved photoemission spectroscopy and X-ray diffraction. At low temps., the 2π/2c-periodic band dispersion, along with half-integer-indexed diffraction peaks along the c axis, unambiguously indicates that the ground state of 1T-TaS2 is a band insulator with interlayer dimerization. Upon heating, however, the system undergoes a transition into a Mott insulating state, which only exists in a narrow temp. window. Our results refute the idea of searching for quantum magnetism in 1T-TaS2 only at low temps., and highlight the competition between on-site Coulomb repulsion and interlayer hopping as a crucial aspect for understanding the material's electronic properties.
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    20. 20
      Cho, D. Nanoscale manipulation of the Mott insulating state coupled to charge order in 1T-TaS2. Nat. Commun. 2016, 7, 10453,  DOI: 10.1038/ncomms10453
      [Crossref], [PubMed], [CAS], Google Scholar
      20
      Nanoscale manipulation of the Mott insulating state coupled to charge order in 1T-TaS2
      Cho, Doohee; Cheon, Sangmo; Kim, Ki-Seok; Lee, Sung-Hoon; Cho, Yong-Heum; Cheong, Sang-Wook; Yeom, Han Woong
      Nature Communications (2016), 7 (), 10453CODEN: NCAOBW; ISSN:2041-1723. (Nature Publishing Group)
      The controllability over strongly correlated electronic states promises unique electronic devices. A recent example is an optically induced ultrafast switching device based on the transition between the correlated Mott insulating state and a metallic state of a transition metal dichalcogenide 1T-TaS2. However, the electronic switching has been challenging and the nature of the transition has been veiled. Here we demonstrate the nanoscale electronic manipulation of the Mott state of 1T-TaS2. The voltage pulse from a scanning tunnelling microscope switches the insulating phase locally into a metallic phase with irregularly textured domain walls in the charge d. wave order inherent to this Mott state. The metallic state is revealed as a correlated phase, which is induced by the moderate redn. of electron correlation due to the charge d. wave decoherence.
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    21. 21
      Venturini, R. Ultra-Efficient Resistance Switching between Charge Ordered Phases in 1T-TaS2 with a Single Picosecond Electrical Pulse. arXiv 2022, 2202.13831
      Google Scholar
      There is no corresponding record for this reference.
    22. 22
      Anders, S. European roadmap on superconductive electronics – status and perspectives. Phys. C Supercond. 2010, 470, 2079– 2126,  DOI: 10.1016/j.physc.2010.07.005
      [Crossref], [CAS], Google Scholar
      22
      European roadmap on superconductive electronics - status and perspectives
      Anders, S.; Blamire, M. G.; Buchholz, F.-Im.; Crete, D.-G.; Cristiano, R.; Febvre, P.; Fritzsch, L.; Herr, A.; Il'ichev, E.; Kohlmann, J.; Kunert, J.; Meyer, H.-G.; Niemeyer, J.; Ortlepp, T.; Rogalla, H.; Schurig, T.; Siegel, M.; Stolz, R.; Tarte, E.; ter Brake, H. J. M.; Toepfer, H.; Villegier, J.-C.; Zagoskin, A. M.; Zorin, A. B.
      Physica C: Superconductivity and Its Applications (Amsterdam, Netherlands) (2010), 470 (23-24), 2079-2126CODEN: PHYCE6; ISSN:0921-4534. (Elsevier B.V.)
      A review. For 4 decades semiconductor electronics has followed Moore's law: with each generation of integration the circuit features became smaller, more complex and faster. This development is now reaching a wall so that smaller is no longer any faster. The clock rate has satd. at about 3-5 GHz and the parallel processor approach will soon reach its limit. The prime reason for the limitation the semiconductor electronics experiences is not the switching speed of the individual transistor, but its power dissipation and thus heat. Digital superconductive electronics is a circuit- and device-technol. that is inherently faster at much less power dissipation than semiconductor electronics. It makes use of superconductors and Josephson junctions as circuit elements, which can provide extremely fast digital devices in a frequency range, dependent on the material, of hundreds of GHz: for example a flip-flop has been demonstrated that operated at 750 GHz. This digital technique is scalable and follows similar design rules as semiconductor devices. Its very low power dissipation of only 0.1 μW per gate at 100 GHz opens the possibility of three-dimensional integration. Circuits like microprocessors and analog-to-digital converters for com. and military applications have been demonstrated. In contrast to semiconductor circuits, the operation of superconducting circuits is based on naturally standardized digital pulses the area of which is exactly the flux quantum Φ0. The flux quantum is also the natural quantization unit for digital-to-analog and analog-to-digital converters. The latter application is so precise, that it is being used as voltage std. and that the phys. unit Volt' is defined by means of this std. Apart from its outstanding features for digital electronics, superconductive electronics provides also the most sensitive sensor for magnetic fields: the Superconducting Quantum Interference Device (SQUID). Amongst many other applications SQUIDs are used as sensors for magnetic heart and brain signals in medical applications, as sensor for geol. surveying and food-processing and for non-destructive testing. As amplifiers of elec. signals, SQUIDs can nearly reach the theor. limit given by Quantum Mechanics. A further important field of application is the detection of very weak signals by transition-edge' bolometers, superconducting nanowire single-photon detectors, and superconductive tunnel junctions. Their application as radiation detectors in a wide frequency range, from microwaves to X-rays is now std. The very low losses of superconductors have led to com. microwave filter designs that are now widely used in the USA in base stations for cellular phones and in military communication applications. The no. of demonstrated applications is continuously increasing and there is no area in professional electronics, in which superconductive electronics cannot be applied and surpasses the performance of classical devices. Superconductive electronics has to be cooled to very low temps. Whereas this was a bottleneck in the past, cooling techniques have made a huge step forward in recent years: very compact systems with high reliability and a wide range of cooling power are available com., from microcoolers of match-box size with milli-Watt cooling power to high-reliability coolers of many Watts of cooling power for satellite applications. Superconductive electronics will not replace semiconductor electronics and similar room-temp. techniques in std. applications, but for those applications which require very high speed, low-power consumption, extreme sensitivity or extremely high precision, superconductive electronics is superior to all other available techniques. To strengthen the European competitiveness in superconductor electronics research projects have to be set-up in the following field:-Ultra-sensitive sensing and imaging. Quantum measurement instrumentation. Advanced analog-to-digital converters. Superconductive electronics technol.
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    23. 23
      Ravnik, J.; Vaskivskyi, I.; Mertelj, T.; Mihailovic, D. Real-time observation of the coherent transition to a metastable emergent state in 1T–TaS2. Phys. Rev. B 2018, 97, 075304,  DOI: 10.1103/PhysRevB.97.075304
      [Crossref], [CAS], Google Scholar
      23
      Real-time observation of the coherent transition to a metastable emergent state in 1T-TaS2
      Ravnik, Jan; Vaskivskyi, Igor; Mertelj, Tomaz; Mihailovic, Dragan
      Physical Review B (2018), 97 (7), 075304CODEN: PRBHB7; ISSN:2469-9969. (American Physical Society)
      The transition to a hidden metastable state in 1T-TaS2 is investigated in real time using coherent time-resolved femtosecond spectroscopy. Relying on spectral differences between phonon modes in the equil. states and in the metastable state, and temp.-tuning the metastable state lifetime, we perform stroboscopic measurements of the electronic response and switching of coherent oscillation frequency through the transition. Very fast coherent switching of the collective-mode frequency is obsd. (∼400fs), comparable to the electronic time scale ∼300fs. A slower, 4.7-ps process is attributed to lattice relaxation. The observations are described well by a fast electronic band structure transformation into the metastable state, consistent with a topol. transition.
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    24. 24
      Landauer, R. Irreversibility and Heat Generation in the Computing Process. IBM journal 1961, 5, 183,  DOI: 10.1147/rd.53.0183
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    25. 25
      Grezes, C. Ultra-low switching energy and scaling in electric-field-controlled nanoscale magnetic tunnel junctions with high resistance-area product. Appl. Phys. Lett. 2016, 108, 012403,  DOI: 10.1063/1.4939446
      [Crossref], [CAS], Google Scholar
      25
      Ultra-low switching energy and scaling in electric-field-controlled nanoscale magnetic tunnel junctions with high resistance-area product
      Grezes, C.; Ebrahimi, F.; Alzate, J. G.; Cai, X.; Katine, J. A.; Langer, J.; Ocker, B.; Khalili Amiri, P.; Wang, K. L.
      Applied Physics Letters (2016), 108 (1), 012403/1-012403/5CODEN: APPLAB; ISSN:0003-6951. (American Institute of Physics)
      The authors reported elec.-field-induced switching with write energies down to 6 fJ/bit for switching times of 0.5 ns, in nanoscale perpendicular magnetic tunnel junctions (MTJs) with high resistance-area product and diams. down to 50 nm. The ultra-low switching energy is made possible by a thick MgO barrier that ensures negligible spin-transfer torque contributions, along with a redn. of the Ohmic dissipation. The authors found that the switching voltage and time are insensitive to the junction diam. for high-resistance MTJs, a result accounted for by a macrospin model of purely voltage-induced switching. The measured performance enables integration with same-size CMOS transistors in compact memory and logic integrated circuits. (c) 2016 American Institute of Physics.
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    26. 26
      Cheng, C. H.; Chin, A.; Yeh, F. S. Ultralow Switching Energy Ni/GeOx/HfON/TaN RRAM. IEEE Electron Device Lett. 2011, 32, 366– 368,  DOI: 10.1109/LED.2010.2095820
      [Crossref], [CAS], Google Scholar
      26
      Ultralow switching energy Ni/GeOx/HfON/TaN RRAM
      Cheng, C. H.; Chin, Albert; Yeh, F. S.
      IEEE Electron Device Letters (2011), 32 (3), 366-368CODEN: EDLEDZ; ISSN:0741-3106. (Institute of Electrical and Electronics Engineers)
      Using stacked covalent-bond-dielec. GeOx on metal-oxynitride HfON, the Ni/GeOx/HfON/TaN resistive random access memory (RRAM) showed ultralow set power of 0.3 μW (0.1 μA at 3 V), reset power of 0.6 nW (-0.3 nA at -1.8 V), fast 20-ns switching time, ultralow 8-fJ switching energy (4-V overstress), and excellent 106 cycling endurance. Such excellent performance was reached by using hopping conduction with neg. temp. coeff. (TC) rather than the pos. TC in metal-oxide RRAM.
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    27. 27
      Wang, L. Voltage-Controlled Magnetic Tunnel Junctions for Processing-In-Memory Implementation. IEEE Electron Device Lett. 2018, 39, 440– 443,  DOI: 10.1109/LED.2018.2791510
      [Crossref], [CAS], Google Scholar
      27
      Voltage-controlled magnetic tunnel junctions for processing-in-memory implementation
      Wang, Lezhi; Kang, Wang; Ebrahimi, Farbod; Li, Xiang; Huang, Yangqi; Zhao, Chao; Wang, Kang L.; Zhao, Weisheng
      IEEE Electron Device Letters (2018), 39 (3), 440-443CODEN: EDLEDZ; ISSN:1558-0563. (Institute of Electrical and Electronics Engineers)
      The processing-in-memory (PIM) paradigm has been considered as a promising alternative to break the bottlenecks of conventional von-Neumann architecture by realizing the unity of data storage and processing in the same die. On the road toward implementing such an architecture, finding a novelmemory that can support both dense data storage and efficient logic processing is the crit. step. In this letter, we report a voltage-controlled magnetic tunnel junction (MTJ), which is a potential candidate for PIM implementation. Stateful Boolean logic functions can be realized with a single device through the memory-like write/read operations. The device was fabricated and characterized at room temp. Afterwards, typical Boolean logic operations, e.g., "OR", "AND", and "NXOR", were exptl. demonstrated with the fabricated MTJ device. The proposed approach opens up a new way for PIM implementation in spintronic memories.
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    28. 28
      Liu, B. Multi-level phase-change memory with ultralow power consumption and resistance drift. Sci. Bull. 2021, 66, 2217– 2224,  DOI: 10.1016/j.scib.2021.07.018
      [Crossref], [CAS], Google Scholar
      28
      Multi-level phase-change memory with ultralow power consumption and resistance drift
      Liu, Bin; Li, Kaiqi; Liu, Wanliang; Zhou, Jian; Wu, Liangcai; Song, Zhitang; Elliott, Stephen R.; Sun, Zhimei
      Science Bulletin (2021), 66 (21), 2217-2224CODEN: SBCUA5; ISSN:2095-9281. (Elsevier B.V.)
      By controlling the amorphous-to-cryst. relative vol., chalcogenide phase-change memory materials can provide multi-level data storage (MLS), which offers great potential for high-d. storage-class memory and neuro-inspired computing. However, this type of MLS system suffers from high power consumption and a severe time-dependent resistance increase ("drift") in the amorphous phase, which limits the no. of attainable storage levels. Here, we report a new type of MLS system in yttrium-doped antimony telluride, utilizing reversible multi-level phase transitions between three states, i.e., amorphous, metastable cubic and stable hexagonal cryst. phases, with ultralow power consumption (0.6-4.3 pJ) and ultralow resistance drift for the lower two states (power-law exponent < 0.007). The metastable cubic phase is stabilized by yttrium, while the evident reversible cubic-to-hexagonal transition is attributed to the sequential and directional migration of Sb atoms. Finally, the decreased heat dissipation of the material and the increase in crystallinity contribute to the overall high performance. This study opens a new way to achieve advanced multi-level phase-change memory without the need for complicated manufg. procedures or iterative programming operations.
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    29. 29
      Loke, D. Breaking the Speed Limits of Phase-Change Memory. Science 2012, 336, 1566– 1569,  DOI: 10.1126/science.1221561
      [Crossref], [PubMed], [CAS], Google Scholar
      29
      Breaking the Speed Limits of Phase-Change Memory
      Loke, D.; Lee, T. H.; Wang, W. J.; Shi, L. P.; Zhao, R.; Yeo, Y. C.; Chong, T. C.; Elliott, S. R.
      Science (Washington, DC, United States) (2012), 336 (6088), 1566-1569CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)
      Phase-change random-access memory (PCRAM) is one of the leading candidates for next-generation data-storage devices, but the trade-off between crystn. (writing) speed and amorphous-phase stability (data retention) presents a key challenge. We control the crystn. kinetics of a phase-change material by applying a const. low voltage via prestructural ordering (incubation) effects. A crystn. speed of 500 ps was achieved, as well as high-speed reversible switching using 500-ps pulses. Ab initio mol. dynamics simulations reveal the phase-change kinetics in PCRAM devices and the structural origin of the incubation-assisted increase in crystn. speed. This paves the way for achieving a broadly applicable memory device, capable of nonvolatile operations beyond gigahertz data-transfer rates.
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      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xoslaksbk%253D&md5=ae63eaaa95d99949e37a2e129bd8af60
    30. 30
      Ding, K. Phase-change heterostructure enables ultralow noise and drift for memory operation. Science 2019, 366, 210– 215,  DOI: 10.1126/science.aay0291
      [Crossref], [PubMed], [CAS], Google Scholar
      30
      Phase-change heterostructure enables ultralow noise and drift for memory operation
      Ding, Keyuan; Wang, Jiangjing; Zhou, Yuxing; Tian, He; Lu, Lu; Mazzarello, Riccardo; Jia, Chunlin; Zhang, Wei; Rao, Feng; Ma, Evan
      Science (Washington, DC, United States) (2019), 366 (6462), 210-215CODEN: SCIEAS; ISSN:1095-9203. (American Association for the Advancement of Science)
      Artificial intelligence and other data-intensive applications have escalated the demand for data storage and processing. New computing devices, such as phase-change random access memory (PCRAM)-based neuro-inspired devices, are promising options for breaking the von Neumann barrier by unifying storage with computing in memory cells. However, current PCRAM devices have considerable noise and drift in elec. resistance that erodes the precision and consistency of these devices. We designed a phase-change heterostructure (PCH) that consists of alternately stacked phase-change and confinement nanolayers to suppress the noise and drift, allowing reliable iterative RESET and cumulative SET operations for high-performance neuro-inspired computing. Our PCH architecture is amenable to industrial prodn. as an intrinsic materials soln., without complex manufg. procedure or much increased fabrication cost.
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    31. 31
      Pi, S. Memristor crossbar arrays with 6-nm half-pitch and 2-nm critical dimension. Nat. Nanotechnol. 2019, 14, 35– 39,  DOI: 10.1038/s41565-018-0302-0
      [Crossref], [PubMed], [CAS], Google Scholar
      31
      Memristor crossbar arrays with 6-nm half-pitch and 2-nm critical dimension
      Pi, Shuang; Li, Can; Jiang, Hao; Xia, Weiwei; Xin, Huolin; Yang, J. Joshua; Xia, Qiangfei
      Nature Nanotechnology (2019), 14 (1), 35-39CODEN: NNAABX; ISSN:1748-3387. (Nature Research)
      The memristor1,2 is a promising building block for next-generation non-volatile memory3, artificial neural networks4-7 and bio-inspired computing systems8,9. Organizing small memristors into high-d. crossbar arrays is crit. to meet the ever-growing demands in high-capacity and low-energy consumption, but this is challenging because of difficulties in making highly ordered conductive nanoelectrodes. Carbon nanotubes, graphene nanoribbons and dopant nanowires have potential as electrodes for discrete nanodevices10-14, but unfortunately these are difficult to pack into ordered arrays. Transfer printing, on the other hand, is effective in generating dense electrode arrays15 but has yet to prove suitable for making fully random accessible crossbars. All the aforementioned electrodes have dramatically increased resistance at the nanoscale16-18, imposing a significant barrier to their adoption in operational circuits. Here we demonstrate memristor crossbar arrays with a 2-nm feature size and a single-layer d. up to 4.5 terabits per square inch, comparable to the information d. achieved using three-dimensional stacking in state-of-the-art 64-layer and multilevel 3D-NAND flash memory19. Memristors in the arrays switch with tens of nanoamperes elec. current with nonlinear behavior. The densely packed crossbar arrays of individually accessible, extremely small functional memristors provide a power-efficient soln. for information storage and processing.
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    32. 32
      Xu, W.; Min, S.-Y.; Hwang, H.; Lee, T.-W. Organic core-sheath nanowire artificial synapses with femtojoule energy consumption. Sci. Adv. 2016, 2, e1501326  DOI: 10.1126/sciadv.1501326
      [Crossref], [PubMed], [CAS], Google Scholar
      32
      Organic core-sheath nanowire artificial synapses with femtojoule energy consumption
      Xu, Wentao; Min, Sung-Yong; Hwang, Hyunsang; Lee, Tae-Woo
      Science Advances (2016), 2 (6), e1501326/1-e1501326/7CODEN: SACDAF; ISSN:2375-2548. (American Association for the Advancement of Science)
      Emulation of biol. synapses is an important step toward construction of large-scale brain-inspired electronics. Despite remarkable progress in emulating synaptic functions, current synaptic devices still consume energy that is orders of magnitude greater than do biol. synapses (∼10 fJ per synaptic event). Redn. of energy consumption of artificial synapses remains a difficult challenge. We report org. nanowire (ONW) synaptic transistors (STs) that emulate the important working principles of a biol. synapse. The ONWs emulate the morphol. of nerve fibers. With a core-sheath-structured ONW active channel and a well-confined 300-nm channel length obtained using ONW lithog., ∼1.23 fJ per synaptic event for individual ONW was attained, which rivals that of biol. synapses. The ONW STs provide a significant step toward realizing low-energy-consuming artificial intelligent electronics and open new approaches to assembling soft neuromorphic systems with nanometer feature size.
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    33. 33
      Havel, V.; Ultrafast switching in Ta2O5-based resistive memories. In 2016 IEEE Silicon Nanoelectronics Workshop (SNW) 82–83; IEEE, 2016;  DOI: 10.1109/SNW.2016.7577995 .
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    34. 34
      Torrezan, A. C.; Strachan, J. P.; Medeiros-Ribeiro, G.; Williams, R. S. Sub-nanosecond switching of a tantalum oxide memristor. Nanotechnology 2011, 22, 485203,  DOI: 10.1088/0957-4484/22/48/485203
      [Crossref], [PubMed], [CAS], Google Scholar
      34
      Sub-nanosecond switching of a tantalum oxide memristor
      Torrezan, Antonio C.; Strachan, John Paul; Medeiros-Ribeiro, Gilberto; Williams, R. Stanley
      Nanotechnology (2011), 22 (48), 485203/1-485203/7CODEN: NNOTER; ISSN:1361-6528. (Institute of Physics Publishing)
      We report sub-nanosecond switching of a metal-oxide-metal memristor utilizing a broadband 20 GHz exptl. setup developed to observe fast switching dynamics. Set and reset operations were successfully performed in the tantalum oxide memristor using pulses with durations of 105 and 120 ps, resp. Reproducibility of the sub-nanosecond switching was also confirmed as the device switched over consecutive cycles.
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    35. 35
      Lee, S.; Sohn, J.; Jiang, Z.; Chen, H.-Y.; Philip Wong, H.-S. Metal oxide-resistive memory using graphene-edge electrodes. Nat. Commun. 2015, 6, 8407,  DOI: 10.1038/ncomms9407
      [Crossref], [PubMed], [CAS], Google Scholar
      35
      Metal oxide-resistive memory using graphene-edge electrodes
      Lee Seunghyun; Sohn Joon; Jiang Zizhen; Chen Hong-Yu; Philip Wong H-S
      Nature communications (2015), 6 (), 8407 ISSN:.
      The emerging paradigm of 'abundant-data' computing requires real-time analytics on enormous quantities of data collected by a mushrooming network of sensors. Todays computing technology, however, cannot scale to satisfy such big data applications with the required throughput and energy efficiency. The next technology frontier will be monolithically integrated chips with three-dimensionally interleaved memory and logic for unprecedented data bandwidth with reduced energy consumption. In this work, we exploit the atomically thin nature of the graphene edge to assemble a resistive memory (∼ 3 ÅA thick) stacked in a vertical three-dimensional structure. We report some of the lowest power and energy consumption among the emerging non-volatile memories due to an extremely thin electrode with unique properties, low programming voltages, and low current. Circuit analysis of the three-dimensional architecture using experimentally measured device properties show higher storage potential for graphene devices compared that of metal based devices.
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    36. 36
      Ando, K. Spin-transfer torque magnetoresistive random-access memory technologies for normally off computing (invited). J. Appl. Phys. 2014, 115, 172607,  DOI: 10.1063/1.4869828
      [Crossref], [CAS], Google Scholar
      36
      Spin-transfer torque magnetoresistive random-access memory technologies for normally off computing (invited)
      Ando, K.; Fujita, S.; Ito, J.; Yuasa, S.; Suzuki, Y.; Nakatani, Y.; Miyazaki, T.; Yoda, H.
      Journal of Applied Physics (Melville, NY, United States) (2014), 115 (17), 172607/1-172607/6CODEN: JAPIAU; ISSN:0021-8979. (American Institute of Physics)
      Most parts of present computer systems are made of volatile devices, and the power to supply them to avoid information loss causes huge energy losses. We can eliminate this meaningless energy loss by utilizing the non-volatile function of advanced spin-transfer torque magnetoresistive random-access memory (STT-MRAM) technol. and create a new type of computer, i.e., normally off computers. Crit. tasks to achieve normally off computers are implementations of STT-MRAM technologies in the main memory and low-level cache memories. STT-MRAM technol. for applications to the main memory was successfully developed by perpendicular STT-MRAMs, and faster STT-MRAM technologies for applications to the cache memory are now being developed. The present status of STT-MRAMs and challenges that remain for normally off computers are discussed. (c) 2014 American Institute of Physics.
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    37. 37
      Jan, G.; Demonstration of Ultra-Low Voltage and Ultra Low Power STT-MRAM designed for compatibility with 0x node embedded LLC applications. In 2018 IEEE Symposium on VLSI Technology 65–66; IEEE, 2018.
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    38. 38
      Rehm, L. Sub-nanosecond switching in a cryogenic spin-torque spin-valve memory element with a dilute permalloy free layer. Appl. Phys. Lett. 2019, 114, 212402,  DOI: 10.1063/1.5094924
      [Crossref], [CAS], Google Scholar
      38
      Sub-nanosecond switching in a cryogenic spin-torque spin-valve memory element with a dilute permalloy free layer
      Rehm, L.; Sluka, V.; Rowlands, G. E.; Nguyen, M.-H.; Ohki, T. A.; Kent, A. D.
      Applied Physics Letters (2019), 114 (21), 212402/1-212402/4CODEN: APPLAB; ISSN:0003-6951. (American Institute of Physics)
      We present a study of pulsed current switching characteristics of spin-valve nanopillars with in-plane magnetized dil. permalloy and undiluted permalloy free layers in the ballistic regime at low temps. The dil. permalloy free layer device switches much faster: the characteristic switching time for a permalloy (Ni0.83Fe0.17) free layer device is 1.18 ns, while that for a dil. permalloy ([Ni0.83Fe0.17]0.6Cu0.4) free layer device is 0.475 ns. A ballistic macrospin model can capture the data trends with a reduced spin-torque asymmetry parameter, reduced spin polarization, and increased Gilbert damping for the dil. permalloy free layer relative to the permalloy devices. Our study demonstrates that reducing the magnetization of the free layer increases the switching speed while greatly reducing the switching energy and shows a promising route toward even lower power magnetic memory devices compatible with superconducting electronics. (c) 2019 American Institute of Physics.
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    39. 39
      Khalili Amiri, P. Electric-Field-Controlled Magnetoelectric RAM: Progress, Challenges, and Scaling. IEEE Trans. Magn. 2015, 51, 1– 7,  DOI: 10.1109/TMAG.2015.2443124
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    40. 40
      Zhao, Q.-Y. A compact superconducting nanowire memory element operated by nanowire cryotrons. Supercond. Sci. Technol. 2018, 31, 035009,  DOI: 10.1088/1361-6668/aaa820
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    41. 41
      McCaughan, A. N.; Toomey, E.; Schneider, M.; Berggren, K. K.; Nam, S. W. A kinetic-inductance-based superconducting memory element with shunting and sub-nanosecond write times. Supercond. Sci. Technol. 2019, 32, 015005,  DOI: 10.1088/1361-6668/aae50d
      [Crossref], [CAS], Google Scholar
      41
      A kinetic-inductance-based superconducting memory element with shunting and sub-nanosecond write times
      McCaughan, Adam N.; Toomey, Emily; Schneider, Michael; Berggren, Karl K.; Nam, Sae Woo
      Superconductor Science and Technology (2019), 32 (1), 015005/1-015005/6CODEN: SUSTEF; ISSN:0953-2048. (IOP Publishing Ltd.)
      We present a kinetic-inductance-based superconducting memory element with non-destructive readout, femtojoule read and write energies, both read and write shunts, which is writeable with pulses shorter than 400 ps. The element utilizes both a high-kinetic-inductance layer made from tungsten silicide as well as a low-kinetic-inductance layer made from niobium. By using tungsten silicide-which has a long (20 ns) thermal time const.-and measuring bit error rates from 10 MHz to 1 GHz, we were able to verify that the thin-film elements could be operated at a data rate at least as fast as the material thermal time const. with a bit error ratio less than 10-6. We also analyze the margins of the device, and outline the characteristics by which a more efficient device may be designed.
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    42. 42
      Konno, G.; Yamanashi, Y.; Yoshikawa, N. Fully Functional Operation of Low-Power 64-kb Josephson-CMOS Hybrid Memories. IEEE Trans. Appl. Supercond. 2017, 27, 1– 7,  DOI: 10.1109/TASC.2016.2646911
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    43. 43
      Krivorotov, I. N.; Ultrafast spin torque memory based on magnetic tunnel junctions with combined in-plane and perpendicular polarizers. In 70th Device Research Conference 211–212; IEEE, 2012.
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    44. 44
      Pickett, M. D.; Stanley Williams, R. Sub-100 fJ and sub-nanosecond thermally driven threshold switching in niobium oxide crosspoint nanodevices. Nanotechnology 2012, 23, 215202,  DOI: 10.1088/0957-4484/23/21/215202
      [Crossref], [PubMed], [CAS], Google Scholar
      44
      Sub-100 fJ and sub-nanosecond thermally driven threshold switching in niobium oxide crosspoint nanodevices
      Pickett, Matthew D.; Williams, R. Stanley
      Nanotechnology (2012), 23 (21), 215202/1-215202/9CODEN: NNOTER; ISSN:1361-6528. (Institute of Physics Publishing)
      We built and measured the dynamical current vs. time behavior of nanoscale niobium oxide crosspoint devices which exhibited threshold switching (current-controlled neg. differential resistance). The switching speeds of 110 × 110 nm2 devices were found to be ΔtON = 700 ps and ΔtOFF = 2.3 ns while the switching energies were of the order of 100 fJ. We derived a new dynamical model based on the Joule heating rate of a thermally driven insulator-to-metal phase transition that accurately reproduced the exptl. results, and employed the model to est. the switching time and energy scaling behavior of such devices down to the 10 nm scale. These results indicate that threshold switches could be of practical interest in hybrid CMOS nanoelectronic circuits.
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    45. 45
      Clerc, S.; A 0.32V, 55fJ per bit access energy, CMOS 65nm bit-interleaved SRAM with radiation Soft Error tolerance. In 2012 IEEE International Conference on IC Design & Technology 1–4; IEEE, 2012;  DOI: 10.1109/ICICDT.2012.6232860 .
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    46. 46
      Wang, K. L.; Alzate, J. G.; Khalili Amiri, P. Low-power non-volatile spintronic memory: STT-RAM and beyond. J. Phys. Appl. Phys. 2013, 46, 074003,  DOI: 10.1088/0022-3727/46/7/074003
      [Crossref], [CAS], Google Scholar
      46
      Low-power non-volatile spintronic memory: STT-RAM and beyond
      Wang, K. L.; Alzate, J. G.; Khalili Amiri, P.
      Journal of Physics D: Applied Physics (2013), 46 (7), 074003CODEN: JPAPBE; ISSN:0022-3727. (IOP Publishing Ltd.)
      The quest for novel low-dissipation devices is one of the most crit. for the future of semiconductor technol. and nano-systems. The development of a low-power, universal memory will enable a new paradigm of non-volatile computation. Here we consider STT-RAM as one of the emerging candidates for low-power non-volatile memory. We show different configurations for STT memory and demonstrate strategies to optimize key performance parameters such as switching current and energy. The energy and scaling limits of STT-RAM are discussed, leading us to argue that alternative writing mechanisms may be required to achieve ultralow power dissipation, a necessary condition for direct integration with CMOS at the gate level for non-volatile logic purposes. As an example, we discuss the use of the giant spin Hall effect as a possible alternative to induce magnetization reversal in magnetic tunnel junctions using pure spin currents. Further, we conc. on magnetoelec. effects, where elec. fields are used instead of spin-polarized currents to manipulate the nanomagnets, as another candidate soln. to address the challenges of energy efficiency and d. The possibility of an elec.-field-controlled magnetoelec. RAM as a promising candidate for ultralow-power non-volatile memory is discussed in the light of exptl. data demonstrating voltage-induced switching of the magnetization and reorientation of the magnetic easy axis by elec. fields in nanomagnets.
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    47. 47
      Dieny, B. Opportunities and challenges for spintronics in the microelectronics industry. Nat. Electron. 2020, 3, 446– 459,  DOI: 10.1038/s41928-020-0461-5
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    48. 48
      Stupakiewicz, A.; Szerenos, K.; Afanasiev, D.; Kirilyuk, A.; Kimel, A. V. Ultrafast nonthermal photo-magnetic recording in a transparent medium. Nature 2017, 542, 71– 74,  DOI: 10.1038/nature20807
      [Crossref], [PubMed], [CAS], Google Scholar
      48
      Ultrafast nonthermal photo-magnetic recording in a transparent medium
      Stupakiewicz, A.; Szerenos, K.; Afanasiev, D.; Kirilyuk, A.; Kimel, A. V.
      Nature (London, United Kingdom) (2017), 542 (7639), 71-74CODEN: NATUAS; ISSN:0028-0836. (Nature Publishing Group)
      Discovering ways to control the magnetic state of media with the lowest possible prodn. of heat and at the fastest possible speeds is important in the study of fundamental magnetism, with clear practical potential. In metals, it is possible to switch the magnetization between two stable states (and thus to record magnetic bits) using femtosecond circularly polarized laser pulses. However, the switching mechanisms in these materials are directly related to laser-induced heating close to the Curie temp. Although several possible routes for achieving all-optical switching in magnetic dielecs. have been discussed, no recording has hitherto been demonstrated. Here we describe ultrafast all-optical photo-magnetic recording in transparent films of the dielec. cobalt-substituted garnet. A single linearly polarized femtosecond laser pulse resonantly pumps specific d-d transitions in the cobalt ions, breaking the degeneracy between metastable magnetic states. By changing the polarization of the laser pulse, we deterministically steer the net magnetization in the garnet, thus writing '0' and '1' magnetic bits at will. This mechanism outperforms existing alternatives in terms of the speed of the write-read magnetic recording event (less than 20 ps) and the unprecedentedly low heat load (less than 6 J/cm3).
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    49. 49
      Dayton, I. M. Experimental Demonstration of a Josephson Magnetic Memory Cell With a Programmable π-Junction. IEEE Magn. Lett. 2018, 9, 1– 5,  DOI: 10.1109/LMAG.2018.2801820
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    50. 50
      Takeshita, Y. High-Speed Memory Driven by SFQ Pulses Based on 0-π SQUID. IEEE Trans. Appl. Supercond. 2021, 31, 1– 6,  DOI: 10.1109/TASC.2021.3060351
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    51. 51
      Tanaka, M. Josephson-CMOS Hybrid Memory With Nanocryotrons. IEEE Trans. Appl. Supercond. 2017, 27, 1– 4,  DOI: 10.1109/TASC.2016.2646929
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    52. 52
      Van Duzer, T. 64-kb Hybrid Josephson-CMOS 4 K RAM With 400 ps Access Time and 12 mW Read Power. IEEE Trans. Appl. Supercond. 2013, 23, 1700504– 1700504,  DOI: 10.1109/TASC.2012.2230294
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    53. 53
      Tolpygo, S. K. Superconductor digital electronics: Scalability and energy efficiency issues (Review Article). Low Temp. Phys. 2016, 42, 361– 379,  DOI: 10.1063/1.4948618
      [Crossref], [CAS], Google Scholar
      53
      Superconductor digital electronics: Scalability and energy efficiency issues (Review Article)
      Tolpygo, Sergey K.
      Low Temperature Physics (2016), 42 (5), 361-379CODEN: LTPHEG; ISSN:1063-777X. (American Institute of Physics)
      Superconductor digital electronics using Josephson junctions as ultrafast switches and magnetic-flux encoding of information was proposed over 30 years ago as a sub-terahertz clock frequency alternative to semiconductor electronics based on complementary metal-oxide-semiconductor (CMOS) transistors. Recently, interest in developing superconductor electronics has been renewed due to a search for energy saving solns. in applications related to high-performance computing. The current state of superconductor electronics and fabrication processes are reviewed in order to evaluate whether this electronics is scalable to a very large scale integration (VLSI) required to achieve computation complexities comparable to CMOS processors. A fully planarized process at MIT Lincoln Lab., perhaps the most advanced process developed so far for superconductor electronics, is used as an example. The process has nine superconducting layers: eight Nb wiring layers with the min. feature size of 350 nm, and a thin superconducting layer for making compact high-kinetic-inductance bias inductors. All circuit layers are fully planarized using chem. mech. planarization (CMP) of SiO2 interlayer dielec. The phys. limitations imposed on the circuit d. by Josephson junctions, circuit inductors, shunt and bias resistors, etc., are discussed. Energy dissipation in superconducting circuits is also reviewed in order to est. whether this technol., which requires cryogenic refrigeration, can be energy efficient. Fabrication process development required for increasing the d. of superconductor digital circuits by a factor of ten and achieving densities above 107 Josephson junctions per cm2 is described. (c) 2016 American Institute of Physics.
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    54. 54
      Enomoto, H.; Kawano, T.; Kawaguchi, M.; Takano, Y.; Sekizawa, K. Van der Waals Growth of Thin TaS 2 on Layered Substrates by Chemical Vapor Transport Technique. Jpn. J. Appl. Phys. 2004, 43, L123– L126,  DOI: 10.1143/JJAP.43.L123
      [Crossref], [CAS], Google Scholar
      54
      Van der Waals growth of thin TaS2 on layered substrates by chemical vapor transport technique
      Enomoto, Hiroyuki; Kawano, Takanori; Kawaguchi, Masayuki; Takano, Yoshiki; Sekizawa, Kazuko
      Japanese Journal of Applied Physics, Part 2: Letters & Express Letters (2004), 43 (2A), L123-L126CODEN: JAPLD8 ISSN:. (Japan Society of Applied Physics)
      Thin TaS2 was prepd. by the van der Waals growth technique coupled with the chem. vapor transport technique using the I2 agent. Hexagonal B nitride (h-BN) and mica, which have layered crystal structures, were used as substrate materials. Thin TaS2 was grown on layered substrates sealed in a quartz ampul. A high-resoln. x-ray diffractometer with a four-crystal monochrometer revealed that very thin 2H-TaS2 film was grown on the surface of the Ag/BN substrate at 300°, where Ag was evapd. on the h-BN substrate surface prior to the film growth. As for the mica substrate, very thin 2H-TaS2 was grown on the substrates with and without Ag modification.
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    55. 55
      Sanders, C. E. Crystalline and electronic structure of single-layer TaS 2. Phys. Rev. B 2016, 94, 081404,  DOI: 10.1103/PhysRevB.94.081404
      [Crossref], [CAS], Google Scholar
      55
      Crystalline and electronic structure of single-layer TaS2
      Sanders, Charlotte E.; Dendzik, Maciej; Ngankeu, Arlette S.; Eich, Andreas; Bruix, Albert; Bianchi, Marco; Miwa, Jill A.; Hammer, Bjoerk; Khajetoorians, Alexander A.; Hofmann, Philip
      Physical Review B (2016), 94 (8), 081404/1-081404/5CODEN: PRBHB7; ISSN:2469-9950. (American Physical Society)
      Single-layer TaS2 is epitaxially grown on Au(111) substrates. The resulting two-dimensional crystals adopt the 1H polymorph. The electronic structure is detd. by angle-resolved photoemission spectroscopy and found to be in excellent agreement with d. functional theory calcns. The single-layer TaS2 is found to be strongly n doped, with a carrier concn. of 0.3(1) extra electrons per unit cell. No superconducting or charge d. wave state is obsd. by scanning tunneling microscopy at temps. down to 4.7 K.
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    56. 56
      Wang, X. Chemical Growth of 1 T -TaS 2 Monolayer and Thin Films: Robust Charge Density Wave Transitions and High Bolometric Responsivity. Adv. Mater. 2018, 30, 1800074,  DOI: 10.1002/adma.201800074
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    57. 57
      Zhao, Q.-Y.; McCaughan, A. N.; Dane, A. E.; Berggren, K. K.; Ortlepp, T. A nanocryotron comparator can connect single-flux-quantum circuits to conventional electronics. Supercond. Sci. Technol. 2017, 30, 044002,  DOI: 10.1088/1361-6668/aa5f33
      [Crossref], [CAS], Google Scholar
      57
      A nanocryotron comparator can connect single-flux-quantum circuits to conventional electronics
      Zhao, Qing-Yuan; McCaughan, Adam N.; Dane, Andrew E.; Berggren, Karl K.; Ortlepp, Thomas
      Superconductor Science and Technology (2017), 30 (4), 044002/1-044002/7CODEN: SUSTEF; ISSN:0953-2048. (IOP Publishing Ltd.)
      Integration with conventional electronics offers a straightforward and economical approach to upgrading existing superconducting technologies, such as scaling up superconducting detectors into large arrays and combining single flux quantum (SFQ) digital circuits with semiconductor logic gates and memories. However, direct output signals from superconducting devices (e.g., Josephson junctions) are usually not compatible with the input requirements of conventional devices (e.g., transistors). Here, we demonstrate the use of a single three-terminal superconducting-nanowire device, called the nanocryotron (nTron), as a digital comparator to combine SFQ circuits with mature semiconductor circuits such as complementary metal oxide semiconductor (CMOS) circuits. Since SFQ circuits can digitize output signals from general superconducting devices and CMOS circuits can interface existing CMOS-compatible electronics, our results demonstrate the feasibility of a general architecture that uses an nTron as an interface to realize a 'super-hybrid' system consisting of superconducting detectors, superconducting quantum electronics, CMOS logic gates and memories, and other conventional electronics.
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    58. 58
      Mraz, A.; Kabanov, V. V.; Mihailovic, D. Nanocryotron-driven Charge Configuration Memory. arXiv 2022, 2203.14586
      Google Scholar
      There is no corresponding record for this reference.
    59. 59
      Mukhanov, O. A.; Kirichenko, A. F.; Filippov, T. V.; Sarwana, S. Hybrid Semiconductor-Superconductor Fast-Readout Memory for Digital RF Receivers. IEEE Trans. Appl. Supercond. 2011, 21, 797– 800,  DOI: 10.1109/TASC.2010.2089409
      [Crossref], [CAS], Google Scholar
      59
      Hybrid semiconductor-superconductor fast-readout memory for digital RF receivers
      Mukhanov, O. A.; Kirichenko, A. F.; Filippov, T. V.; Sarwana, S.
      IEEE Transactions on Applied Superconductivity (2011), 21 (3, Pt. 1), 797-800CODEN: ITASE9; ISSN:1051-8223. (Institute of Electrical and Electronics Engineers)
      Results of the development of a new type of a hybrid memory for superconducting Digital-RF receivers supporting 30 Gbps memory readout speed are presented. The main feature of this memory is a combination of a high capacity room-temp. memory and a high speed on-chip superconductive cache in order to provide digital waveform templates for Digital-RF signal processing. As a room-temp. high-capacity memory with fast readout, we selected Sympuls pattern generator BMG 30 G-64 M capable of producing a 30 Gbps serial data stream of programmable pattern of 67,108,864 bits. We designed, fabricated, and tested an on-chip cache which receives high-speed template serial data from the room temp. memory and converts it into a stream of 3-bit words of template of local oscillator (LO) for digital mixer. We integrated the memory with a 1 × 3-bit digital I/Q mixer (1-bit digitized RF stream multiplied by 3-bit digital LO).
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    60. 60
      Joshi, J. Charge density wave activated excitons in TiSe2–MoSe2 heterostructures. APL Mater. 2022, 10, 011103,  DOI: 10.1063/5.0067098
      [Crossref], [CAS], Google Scholar
      60
      Charge density wave activated excitons in TiSe2-MoSe2 heterostructures
      Joshi, Jaydeep; Scharf, Benedikt; Mazin, Igor; Krylyuk, Sergiy; Campbell, Daniel J.; Paglione, Johnpierre; Davydov, Albert; Zutic, Igor; Vora, Patrick M.
      APL Materials (2022), 10 (1), 011103CODEN: AMPADS; ISSN:2166-532X. (American Institute of Physics)
      Layered materials enable the assembly of a new class of heterostructures where lattice-matching is no longer a requirement. Interfaces in these heterostructures therefore become a fertile ground for unexplored physics as dissimilar phenomena can be coupled via proximity effects. In this article, we identify an unexpected photoluminescence (PL) peak when MoSe2 interacts with TiSe2. A series of temp.-dependent and spatially resolved PL measurements reveal that this peak is unique to the TiSe2-MoSe2 interface, is higher in energy compared to the neutral exciton, and exhibits exciton-like characteristics. The feature disappears at the TiSe2 charge d. wave transition, suggesting that the d. wave plays an important role in the formation of this new exciton. We present several plausible scenarios regarding the origin of this peak that individually capture some aspects of our observations but cannot fully explain this feature. These results therefore represent a fresh challenge for the theor. community and provide a fascinating way to engineer excitons through interactions with charge d. waves. (c) 2022 American Institute of Physics.
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