Temperature-dependent coherent phonon dynamics in Bi<sub>2</sub>Te<sub>3</sub>

POSTER

Abstract

In this work, temperature-dependent(78K~290K) coherent phonon dynamics in topological insulator Bi2Te3 are investigated. Four coherent phonon types(A1g1, A1g2, Eg, coherent acoustic phonon) with strong temperature dependency are observed in transmission pump-probe spectroscopy at low temperature(78K, 90K).These could be attributed to temperature dependent gradient force which resulting in the coherent phonons generation. Especially, lifetime of around 2.87ps for Eg phonon mode is observed for the first time.The depressing signal of reflective pump probe due to the enhancing absorption of surface state for thin film topological insulator will be accordingly increasing as temperature cooling is proposed.

*The authors would like to thank financial support by the grant of Ministry of Science and Technology under the project number of MOST 106-2112-M-110-006-MY3 and MOST 107-2218-E-110-016.

Presenters

  • Tsun-I Chen

    • Department of Photonics, National Sun Yat-sen University

Authors

  • Tsun-I Chen

    • Department of Photonics, National Sun Yat-sen University

  • Jin-Wei Li

    • Department of Photonics, National Sun Yat-sen University

  • Hsuan-Yin Chen

    • Department of Photonics, National Sun Yat-sen University

  • Jung-Chun Huang

    • Department of Physics, National Cheng Kung University

  • Meng-Qing Lee

    • Department of Photonics, National Sun Yat-sen University

  • Chao-Kuei Lee

    • National Sun Yat-sen University
    • Department of Photonics, National Sun Yat-sen University
    • Photonics, National Sun Yat-sen university
    • Department of Photonics, National Sun Yat-sen University, Taiwan