Anomalous phonon softening in the topological insulator Sn-doped Bi1.1Sb0.9Te2S  

作　　者：BoWen Li WenChao Jiang GuanYu Chen Ying Xiang Wei Xie YaoMin Dai XiYu Zhu Huan Yang Hai-Hu Wen 

机构地区：[1]Center for Superconducting Physics and Materials,National Laboratory of Solid State Microstructures and Department of Physics,National Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing 210093,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2020年第11期85-89,共5页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.11874206);the Fundamental Research Funds for the Central Universities(Grant No.020414380095)。

摘　　要：Investigations into the phonon behavior provide important information on interactions between different excitations in quantum materials.We perform a detailed study of the phonon behavior in the topological insulator Sn-doped Bi1.1Sb0.9Te2S using infrared spectroscopy.We observe two IR-active phonon modes at about 64 and 165 cm^1,which are labeled withαandβ,respectively.While the evolution of theβmode with temperature can be well described by the expected anharmonic decay process,theαmode shifts to lower frequencies with decreasing temperature.Such an anomalous softening of theαmode may arise from the charged-phonon effect due to the coupling between this mode and the topological surface states in Sn-doped Bi1.1Sb0.9Te2S.

关 键 词：topological insulator infrared spectroscopy PHONON 

分 类 号：O469[理学—凝聚态物理]