Coulomb impurity scattering in topological insulator thin films
- Texas Center for Superconductivity and Department of Physics, University of Houston, Houston, Texas 77204 (United States)
Inter-surface coupling in thin-film topological insulators can reduce the surface state mobility by an order of magnitude in low-temperature transport measurements. The reduction is caused by a reduction in the group velocity and an increased s{sub z} component of the surface-state spin which weakens the selection rule against large-angle scattering. An intersurface potential splits the degenerate bands into a Rashba-like bandstructure. This reduces the intersurface coupling, it largely restores the selection rule against large angle scattering, and the ring-shaped valence band further reduces backscattering by requiring, on average, larger momentum transfer for backscattering events. The effects of temperature, Fermi level, and intersurface potential on the Coulomb impurity scattering limited mobility are analyzed and discussed.
- OSTI ID:
- 22311161
- Journal Information:
- Applied Physics Letters, Vol. 105, Issue 3; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
Similar Records
Electrostatic Coupling between Two Surfaces of a Topological Insulator Nanodevice
Surface and substrate induced effects on thin films of the topological insulators Bi2Se3 and Bi2Te3