Optical spectroscopy study of charge density wave orderOptical spectroscopy study of charge density wave order in Sr_3Rh_4Sn_(13) and (Sr_(0.5)Ca_(0.5))3_Rh_4Sn_(13)  

作　　者：Qian Wan KuiJuan Jin JieSu Wang HongBao Yao JunXing Gu HaiZhong Guo XiuLai Xu GuoZhen Yang 

机构地区：[1]Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences [2]University of Chinese Academy of Sciences [3]Collaborative Innovation Center of Quantum Matter

出　　处：《Science China(Physics,Mechanics & Astronomy)》2017年第4期57-61,共5页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Key Basic Research Program of China(Grant Nos.2014CB921001,and 2013CB328706);the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(GrantNo.QYZDJ-SSW-SLH020);the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant No.XDB07030200);the National Natural Science Foundation of China(Grant Nos.11574365,11474349,11674385,11404380,91436101,and 61275060)

摘　　要：The ultrafast laser-excited magnetization dynamics of ferromagnetic （FM） La0.67Sr0.33MnO3 （LSMO） thin films with BiFeO3 （BFO） coating layers grown by laser molecular beam epitaxy are investigated using the optical pump-probe technique. Uniform magnetization precessions are observed in the films under an applied external magnetic field by measuring the time-resolved magneto-optical Kerr effect. The magnetization precession frequencies of the LSMO thin films with the BFO coating layers are lower than those of uncoated LSMO films, which is attributed to the suppression of the anisotropy field induced by the exchange interaction at the interface between the antiferromagnetic order of BFO and the FM order of LSMO.We perform optical spectroscopy measurement on single-crystal samples of Sr_3Rh_4Sn_(13) and(Sr_(0.5)Ca_(0.5))_3Rh_4Sn_(13).Formation of CDW energy gap was clearly observed for both single-crystal samples when they undergo the phase transitions.The existence of residual Drude components in σ_1(ω) below T_(Cdw) indicates that the Fermi surface is only partially gapped in the CDW state.The obtained value of 2△/k_BT_(CDW) is roughly 13 for both Sr_3Rh_4Sn_(13) and(Sr_(0.5)Ca_(0.5))_3Rh_4Sn_(13) compounds,which is considerably larger than the mean-field value based on the weak-coupling BCS theory.The measurements provide optical evidence for the strong coupling characteristics of the CDW phase transition.

关 键 词：magnetization precession ultrafast time-resolved magneto-optical Kerr effect perovskite oxide interface 

分 类 号：N[自然科学总论]