Anisotropic phonon dynamics in Dirac semimetal PtTe2 thin films enabled by helicity-dependent ultrafast light excitation  

作　　者：Ziyang Li Yequan Chen Anke Song Jinzhong Zhang Rong Zhang Zongzhi Zhang Xuefeng Wang 

机构地区：[1]Key Laboratory of Micro and Nano Photonic Structures(MOE),School of Information Science and Technology,Fudan University,Shanghai,China [2]Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials,State Key Laboratory of Spintronics Devices and Technologies,School of Electronic Science and Engineering,Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing,China [3]Department of Physics,School of Physics and Electronic Science,East China Normal University,Shanghai,China [4]Department of Physics,Xiamen University,Xiamen,China

出　　处：《Light(Science & Applications)》2024年第9期1888-1897,共10页光（科学与应用)（英文版）

基　　金：supported by the National Key R&D Program of China(2022YFA1402404);the National Natural Science Foundation of China(12374104,52171230,T2394473,T2394470,62274085,61822403 and 11874120);the Fundamental Research Funds for the Central Universities(021014380225).

摘　　要：Coherent phonons have aroused considerable attention in condensed matter physics owing to their extraordinary capacity of reflecting and controlling the physical properties of matter.However,the investigation on the interaction between coherent phonons and other microscopic particles on the ultrafast timescale within topological systems continues to be an active and unresolved area.Here,we show the energy transfer of coherent optical phonons(COP)in Dirac semimetal PtTe2 thin films using ultrafast optical pump-probe spectroscopy.Specifically,the helicitydependent light-driven anisotropic COP signals disclose their direct connection with the light-excited anisotropic spinpolarized electrons via an angular momentum transfer.Furthermore,we observe the notable decreases in the COP oscillation frequency and the decay rate with increasing temperatures due to the anharmonic phonon-phonon scattering and electron-phonon scattering in the COP dissipation process,respectively.Our work paves the way for uncovering the coherent phonons in Dirac semimetals for the potential applications in optoelectronics and optospintronics.

关 键 词：spectroscopy PHONON DIRAC 

分 类 号：O57[理学—粒子物理与原子核物理]