Dynamical evolution of anisotropic response of type-Ⅱ Weyl semimetal TalrTe_(4) under ultrafast photoexcitation  

作　　者：Xiao Zhuo Jiawei Lai Peng Yu Ze Yu Junchao Ma Wei Lu Miao Liu Zheng Liu Dong Sun 

机构地区：[1]International Center for Quantum Materials,School of Physics,Peking University,100871 Beijing,China. [2]State Key Laboratory of Optoelectronic Materials and Technologies,School of Materials Scierice and Engineering,Sun Yat-sen University,510275 Guangzhou,Guangdong,China. [3]Centre for Programmed Materials,School of Materials Science and Engineering,Nanyang Technological University,Singapore 639798,Sin gapore. [4]ln stitute of Physics,Chinese Academy of Sciences,100190 Beijing,China. [5]State Key Laboratory of Precision Measurement Technology and In struments,School of Precision Instruments and Opto-electronics Engineering,Tianjin University,No.92 Weijin Road,300072 Tianjin,China. [6]Songshan Lake Materials Laboratory,523808 Dongguan,Guangdong,China. [7]Collaborative Inno vati on Center of Quantum Matter,100871 Beijing,China

出　　处：《Light(Science & Applications)》2021年第6期1053-1060,共8页光（科学与应用)（英文版）

基　　金：the National Key Research and Development Program of China(2020YFA0308800);the National Natural Science Foundation of China(NSFC Grants Nos.12034001,11674013,91750109);Beijing Nature Science Foundation(JQ19001);.J.L.is also supported by China National Postdoctoral for Innovative Talent(BX2O2OOO15);Z.L.and P.Y.acknowledge support from the Singapore National Research Foundation under NRF award number NRF-RF2013-08,MOE Tier 2 MOE2016-T2-2-153,and MOE2017-T2-2-136.P.Y.is also supported by 100 Top Talents Program(No.29000-18841216)of Sun Yat-sen University.

摘　　要：Layered type-ⅡWeyl semimetals,such as WTe_(2)/MoTe_(2),and TalrTe_(4)have been dem on strated as a supreme photodetection material with topologically enhanced responsivity and specific sensitivity to the orbital angular momentum of light.Toward future device applications with high performance and ultrafast response,it is necessary to understand the dynamical processes of hot carriers and transient electronic properties of these materials under photoexcitation.In this work,mid-infrared ultrafast spectroscopy is performed to study the dynamical evolution of the anisotropic response of TalrTe_(4).The dynamical relaxation of photoexcited carriers exhibits three exponential decay components relating to optical/acoustic phonon cooling and subsequent heat transfer to the substrate.The ultrafast transient dynamics imply that TalrTe_(4)is an ideal material candidate for ultrafast optoelectronic applications,especially in the Iong-wavelength region.The angle-resolved measurement of transient reflection reveals that the reflectivity becomes less anisotropic in the quasi-equilibrium state,indicating a reduction in the anisotropy of dynamical conductivity in presence of photoexcited hot carriers.The results are indispensable in material engineering for polarization-sensitive optoelectronics and high field electronics.

关 键 词：polarization ANISOTROPIC TRANSIENT 

分 类 号：TB33[一般工业技术—材料科学与工程]