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

5 Scopus citations


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
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
ISSN (Print)0277-786X


ConferenceUltrafast Phenomena and Nanophotonics XVII
Country/TerritoryUnited States
CitySan Francisco, CA


  • Pump-probe spectroscopy
  • Topological insulators
  • Ultrafast dynamics


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