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Title: Temperature-dependent carrier–phonon coupling in topological insulator Bi{sub 2}Se{sub 3}

Temperature-dependent (11.0 K−294.5 K) carrier–phonon coupling in Bi{sub 2}Se{sub 3} is investigated by ultrafast pump−probe spectroscopy. The rise time of the differential reflectivity is interpreted by a combined effect of electron temperature relaxation and hot-phonon lifetime. The electron−phonon coupling constant of the bulk state (λ=0.63±0.05) is deduced from theoretical fitting. Increasing hot-phonon lifetime with decreasing temperature is attributed to a decreasing phonon−phonon collision rate. A complete analysis of the thermalization process is presented. Understanding carrier and phonon dynamics is essential for future optoelectronic and spintronic applications of topological insulators.
Authors:
;  [1] ; ;  [2]
  1. Electrical Engineering Department, University of California Los Angeles, Los Angeles, California 90095 (United States)
  2. Department of Electrophysics, National Chiao-Tung University, Hsinchu 300, Taiwan (China)
Publication Date:
OSTI Identifier:
22395474
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 23; 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; BISMUTH SELENIDES; CHARGE CARRIERS; COUPLING; COUPLING CONSTANTS; ELECTRON TEMPERATURE; LIFETIME; PHONONS; PULSE RISE TIME; REFLECTIVITY; RELAXATION; TEMPERATURE DEPENDENCE; THERMALIZATION; TOPOLOGY