Dirac semimetal PdTe2 temperature-dependent quasiparticle dynamics and electron–phonon coupling

Results in Physics

You-Guo Shi¹  Zi-Teng Liu¹  Jian-Qiao Meng²  Peng-Bo Song³  Hao Liu³  Xiao-Fang Tang⁴  Han Huang⁴  Ya-Hua Yuan⁴  Yu-Xia Duan⁴  Shuang-Xing Zhu⁴  Chen Zhang⁴  Jun He⁴  Fan-Ying Wu⁴  Qi-Yi Wu⁴  Jiao-Jiao Song⁴  H.Y. Liu⁴  Yin-Zou Zhao⁴  Shu-Yu Liu⁴ 

[1] School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China;Beijing Academy of Quantum Information Sciences, Beijing 100085, China;Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;School of Physics and Electronics, Central South University, Changsha 410083, Hunan, China;

关键词: Electron-phonon coupling;    Superconductivity;    Ultrafast spectroscopy;   

DOI  :  

来源: DOAJ

【 摘 要 】

Dirac semimetal PdTe2 single-crystal temperature-dependent ultrafast carrier and phonon dynamics were studied using ultrafast optical pump-probe spectroscopy. Quantitative analysis revealed a fast relaxation process (τf) occurring at a subpicosecond time scale originating from electron–phonon thermalization. This rapid relaxation was followed by a slower relaxation process (τs) on a time scale of ∼ 7-9.5 ps which originated from phonon-assisted electron–hole recombination. Two significant vibrational modes resolved at all measured temperatures. These modes corresponded to in-plane (Eg), and out-of-plane (A1g), Te atoms motion. Test results suggested that pure dephasing played an important role in the relaxation processes. Analysis of the electron–phonon coupling constant suggested that the A1gmode contributes greatly to the superconductivity, and high-frequency phonons are also involved forming of Cooper pairs. Our observations should improve the understanding of complex superconductivity of PdTe2.

【 授权许可】

Unknown