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

doi:10.1117/12.2001954

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 proceeding › Conference contribution › peer-review

6 Scopus citations

Abstract

Ultrafast dynamics of carriers and phonons in topological insulators Cu_xBi₂Se_3-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 (A_1g ¹). According to the red shift of A_1g ¹ phonon frequency, the Cu atoms in Cu_xBi₂Se₃ 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 language	English
Title of host publication	Ultrafast Phenomena and Nanophotonics XVII
Number of pages	7
DOIs	https://doi.org/10.1117/12.2001954
State	Published - 2013
Event	Ultrafast Phenomena and Nanophotonics XVII - San Francisco, CA, United States Duration: 3 Feb 2013 → 6 Feb 2013

Publication series

Name	Proceedings of SPIE - The International Society for Optical Engineering
Volume	8623
ISSN (Print)	0277-786X

Conference

Conference	Ultrafast Phenomena and Nanophotonics XVII
Country/Territory	United States
City	San Francisco, CA
Period	3/02/13 → 6/02/13

Keywords

Pump-probe spectroscopy
Topological insulators
Ultrafast dynamics

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10.1117/12.2001954

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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. (2013). Ultrafast dynamics in topological insulators. In Ultrafast Phenomena and Nanophotonics XVII Article 86230D (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 8623). https://doi.org/10.1117/12.2001954

@inproceedings{e83b1625a12a4170b7701fe3466bdb0e,

title = "Ultrafast dynamics in topological insulators",

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.",

keywords = "Pump-probe spectroscopy, Topological insulators, Ultrafast dynamics",

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

year = "2013",

doi = "10.1117/12.2001954",

language = "English",

isbn = "9780819493927",

series = "Proceedings of SPIE - The International Society for Optical Engineering",

booktitle = "Ultrafast Phenomena and Nanophotonics XVII",

note = "Ultrafast Phenomena and Nanophotonics XVII ; Conference date: 03-02-2013 Through 06-02-2013",

}

Luo, C-W, Chen, HJ, Wang, HJ, Ku, SA, Wu, K-H, Uen, TM, Juang, J-Y , Lin, J-Y , Young, B-L, Kobayashi, T, Sankar, R, Chou, FC, Berger, H & Gu, GD 2013, Ultrafast dynamics in topological insulators. in Ultrafast Phenomena and Nanophotonics XVII., 86230D, Proceedings of SPIE - The International Society for Optical Engineering, vol. 8623, Ultrafast Phenomena and Nanophotonics XVII, San Francisco, CA, United States, 3/02/13. https://doi.org/10.1117/12.2001954

TY - GEN

T1 - Ultrafast dynamics in topological insulators

AU - Luo, Chih-Wei

AU - Chen, H. J.

AU - Wang, H. J.

AU - Ku, S. A.

AU - Wu, Kaung-Hsiung

AU - Uen, T. M.

AU - Juang, Jenh-Yih

AU - Lin, Jiunn-Yuan

AU - Young, Ben-Li

AU - Kobayashi, T.

AU - Sankar, R.

AU - Chou, F. C.

AU - Berger, H.

AU - Gu, G. D.

PY - 2013

Y1 - 2013

N2 - 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.

AB - 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.

KW - Pump-probe spectroscopy

KW - Topological insulators

KW - Ultrafast dynamics

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DO - 10.1117/12.2001954

M3 - Conference contribution

AN - SCOPUS:84878181359

SN - 9780819493927

T3 - Proceedings of SPIE - The International Society for Optical Engineering

BT - Ultrafast Phenomena and Nanophotonics XVII

T2 - Ultrafast Phenomena and Nanophotonics XVII

Y2 - 3 February 2013 through 6 February 2013

ER -

Ultrafast dynamics in topological insulators

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