標題: Ultrafast dynamics in topological insulators
作者: Luo, C. W.
Chen, H. -J.
Wang, H. J.
Ku, S. A.
Wu, K. H.
Uen, T. M.
Juang, J. Y.
Lin, J. -Y.
Young, B. L.
Kobayashi, T.
Sankar, R.
Chou, F. C.
Berger, H.
Gu, G. D.
電子物理學系
Department of Electrophysics
關鍵字: Ultrafast dynamics;topological insulators;pump-probe spectroscopy
公開日期: 2013
摘要: 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 (Delta R/R), which is assigned to the coherent optical phonon (A(1g)(1)). According to the red shift of A(1g)(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 Delta R/R, which is assigned to carrier relaxation in Dirac cone, is 1.62 ps and 20.5 ps, respectively.
URI: http://hdl.handle.net/11536/22495
http://dx.doi.org/10.1117/12.2001954
ISBN: 978-0-8194-9392-7
ISSN: 0277-786X
DOI: 10.1117/12.2001954
期刊: ULTRAFAST PHENOMENA AND NANOPHOTONICS XVII
Volume: 8623
Appears in Collections:Conferences Paper


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