Temperature-dependent carrier–phonon coupling in topological insulator Bi2Se3
Abstract
Temperature-dependent (11.0 K−294.5 K) carrier–phonon coupling in Bi2Se3 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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 08, 2014
- Source ID
- 10.1063/1.4904009
Entities
People
- Hsueh-ju Chen
- Jia-ming Liu
- Kuang-hsiung Wu
- Yi-ping Lai
Organizations
- National Chiao Tung University
- National Science and Technology Council
- United States Air Force
- University of California