Weak-value amplification for the optical signature of topological phase transitions  

作　　者：WEIJIE WU SHIZHEN CHEN WENHAO XU ZHENXING LIU RUNNAN LOU LIHUA SHEN HAILU LUO SHUANGCHUN WEN XIAOBO YIN 

机构地区：[1]Laboratory for Spin Photonics,School of Physics and Electronics,Hunan University,Changsha 410082,China [2]Department of Mechanical Engineering,University of Colorado,Boulder,Colorado 80309,USA [3]Materials Science and Engineering Program,University of Colorado,Boulder,Colorado 80309,USA

出　　处：《Photonics Research》2020年第12期I0015-I0022,共8页光子学研究（英文版）

基　　金：National Natural Science Foundation of China(61835004);China Scholarship Council(201806130121);Hunan Provincial Innovation Foundation for Postgraduate(CX20200424).

摘　　要：We show that weak measurements can be used to measure the tiny signature of topological phase transitions.The signature is an in-plane photonic spin Hall effect,which can be described as a consequence of a Berry phase.It is also parallel to the propagation direction of a light beam.The imaginary part of the weak value can be used to analyze ultrasmall longitudinal phase shifts in different topological phases.These optical signatures are related to the Chern number and bandgaps;we also use a preselection and postselection technique on the spin state to enhance the original signature.The weak amplification technique offers a potential way to determine the spin and valley properties of charge carriers,Chern numbers,and topological phases by direct optical measurement.

关 键 词：SIGNATURE TOPOLOGICAL TRANSITIONS 

分 类 号：O469[理学—凝聚态物理]