Ultrafast dynamics in topological insulators

Chih-Wei Luo, H. J. Chen, H. J. Wang, S. A. Ku, Kaung-Hsiung Wu, T. M. Uen, Jenh-Yih Juang, Jiunn-Yuan Lin, Ben-Li Young, T. Kobayashi, R. Sankar, F. C. Chou, H. Berger, G. D. Gu

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

2 Scopus citations

Abstract

Ultrafast dynamics of carriers and phonons in topological insulators CuxBi2Se3-y (x=0, 0.1, 0.125, y=0, 1) was studied using femtosecond optical pump-probe spectroscopy. One damped oscillation was clearly observed in the transient reflectivity changes (ΔR/R), which is assigned to the coherent optical phonon (A1g 1). According to the red shift of A1g 1 phonon frequency, the Cu atoms in CuxBi2Se3 crystals may predominantly intercalated between pair of the quintuple layers. Moreover, the carrier dynamics in the Dirac-cone surface state is significantly different from that in bulk state, which was investigated using optical pump mid-infrared (mid-IR) probe spectroscopy. The rising time and decay time of the negative component in ΔR/R, which is assigned to carrier relaxation in Dirac cone, is 1.62 ps and 20.5 ps, respectively.

Original languageEnglish
Title of host publicationUltrafast Phenomena and Nanophotonics XVII
Number of pages7
DOIs
StatePublished - 30 May 2013
EventUltrafast Phenomena and Nanophotonics XVII - San Francisco, CA, United States
Duration: 3 Feb 20136 Feb 2013

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume8623
ISSN (Print)0277-786X

Conference

ConferenceUltrafast Phenomena and Nanophotonics XVII
CountryUnited States
CitySan Francisco, CA
Period3/02/136/02/13

Keywords

  • Pump-probe spectroscopy
  • Topological insulators
  • Ultrafast dynamics

Fingerprint Dive into the research topics of 'Ultrafast dynamics in topological insulators'. Together they form a unique fingerprint.

Cite this