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Title: Coulomb impurity scattering in topological insulator thin films

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.
Authors:
; ;  [1] ;  [2]
  1. Department of Electrical Engineering, University of California, Riverside, California 92521 (United States)
  2. Texas Center for Superconductivity and Department of Physics, University of Houston, Houston, Texas 77204 (United States)
Publication Date:
OSTI Identifier:
22311161
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 3; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; BACKSCATTERING; CARRIER MOBILITY; COUPLING; DIELECTRIC MATERIALS; FERMI LEVEL; IMPURITIES; MOMENTUM TRANSFER; SCATTERING; SELECTION RULES; SPIN; SURFACES; THIN FILMS; TOPOLOGY