Topological Phase Buried in a Chalcogenide Superlattice Monitored by Helicity-Dependent Kerr Measurement
- Richarj Mondal*Richarj Mondal*E-mail: [email protected] (R.M.).Division of Applied Physics, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8573, JapanMore by Richarj Mondal,
- Yuki AiharaYuki AiharaDivision of Applied Physics, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8573, JapanMore by Yuki Aihara,
- Yuta SaitoYuta SaitoNanoelectronics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 5, 1-1-1 Higashi, Tsukuba 305-8565, JapanMore by Yuta Saito,
- Paul FonsPaul FonsNanoelectronics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 5, 1-1-1 Higashi, Tsukuba 305-8565, JapanMore by Paul Fons,
- Alexander V. KolobovAlexander V. KolobovNanoelectronics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 5, 1-1-1 Higashi, Tsukuba 305-8565, JapanMore by Alexander V. Kolobov,
- Junji TominagaJunji TominagaNanoelectronics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 5, 1-1-1 Higashi, Tsukuba 305-8565, JapanMore by Junji Tominaga, and
- Muneaki Hase*Muneaki Hase*E-mail: [email protected] (M.H.).Division of Applied Physics, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8573, JapanNanoelectronics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 5, 1-1-1 Higashi, Tsukuba 305-8565, JapanMore by Muneaki Hase
Abstract
Chalcogenide superlattices (SLs), formed by the alternate stacking of GeTe and Sb2Te3 layers, also referred to as interfacial phase-change memory (iPCM), are a leading candidate for spin-based memory device applications. Theoretically, the iPCM structure has been predicted to form a three-dimensional topological insulator or Dirac semimetal phase depending on the constituent layer thicknesses. Here, we experimentally investigate the topological insulating nature of chalcogenide SLs using a helicity-dependent time-resolved Kerr measurement. The helicity-dependent Kerr signal is observed to exhibit a four-cycle oscillation with π/2 periodicity, suggesting the existence of a Dirac-like cone in some chalcogenide SLs. Furthermore, we found that increasing the thickness of the GeTe layer dramatically changed the periodicity, indicating a phase transition from a Dirac semimetal into a trivial insulator. Our results demonstrate that thickness-tuned chalcogenide SLs can play an important role in the manipulation of topological states, which may open up new possibilities for spintronic devices based on chalcogenide SLs.
Cited By
This article is cited by 2 publications.
- Takara Suzuki, Richarj Mondal, Yuta Saito, Paul Fons, Alexander V Kolobov, Junji Tominaga, Hidemi Shigekawa, Muneaki Hase. Photon energy dependence of Kerr rotation in GeTe/Sb 2 Te 3 chalcogenide superlattices. Journal of Physics: Condensed Matter 2019, 31 (41) , 415502. https://doi.org/10.1088/1361-648X/ab2e9f
- Yu Kyoung Ryu, Riccardo Frisenda, Andres Castellanos-Gomez. Superlattices based on van der Waals 2D materials. Chemical Communications 2019, 55 (77) , 11498-11510. https://doi.org/10.1039/C9CC04919C