A topological phase buried in a chalcogenide superlattice monitored by a helicity dependent Kerr measurement
arXiv:1907.11828 · doi:10.1021/acsami.8b07974
Abstract
Chalcogenide superlattices (SL), formed by the alternate stacking of GeTe and SbTe layers, also referred to as interfacial phase change memory (iPCM), are a leading candidate for spin based memory device applications. Theoretically, the iPCM structure it has been predicted to form a 3D topological insulator or Dirac semimetal 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 /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 changes 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.
arXiv comment18 pages, 4 figures
References in corpus (21)
- Topological Insulators
- Topological insulators and superconductors
- Topological Insulators in Three Dimensions
- Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
- Topological Field Theory of Time-Reversal Invariant Insulators
- Topological entanglement entropy
- Weyl Semimetal in a Topological Insulator Multilayer
- New Perspectives for Rashba Spin-Orbit Coupling
- First observation of Spin-Momentum Helical Locking in Bi2Se3 and Bi2Te3, demonstration of Topological-Order at 300K and a realization of topological-transport-regime
- Crossover of Three-Dimensional Topological Insulator of Bi2Se3 to the Two-Dimensional Limit
- First direct observation of Spin-textures in Topological Insulators : Spin-resolved ARPES as a probe of topological quantum spin Hall effect and Berry's phase
- Topological Surface States Protected From Backscattering by Chiral Spin Texture
- Landau quantization and the thickness limit of topological insulator thin films of Sb2Te3
- Ferroelectricity and Rashba effect in GeTe
- Ferroelectric control of the spin texture in germanium telluride
- Manipulation of Topological States and Bulk Band Gap Using Natural Heterostructures of a Topological Insulator
- Topological insulating behaviour in conducting property of crystalline Ge-Sb-Te
- A new superconductor derived from topological insulator heterostructure
- Engineering Topological Surface States and Giant Rashba Spin Splitting in BiTeI/BiTe Heterostructures
- Weyl node assisted conductivity switch in interfacial phase change memory with van der Waals interfaces
- A cascading nonlinear magneto-optical effect in topological insulators