量子反常霍尔效应研究进展  

Recent progress in the research of quantum anomalous Hall effect

作　　者：冯硝 何珂[1] 王亚愚 马旭村[1] 吕力[2] 薛其坤[1] Xiao Feng;Ke He;Yayu Wang;Xucun Ma;Li Lü;Qi-Kun Xue(State Key Laboratory of Low Dimensional Quantum Physics,Department of Physics,Tsinghua University,Beijing 100084,China;Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]清华大学物理系低维量子物理国家重点实验室,北京100084 [2]中国科学院物理研究所,北京100190

出　　处：《科学通报》2020年第9期800-809,共10页Chinese Science Bulletin

基　　金：国家重点基础研究发展计划(2018YFA0307100,2017YFA0303303);国家自然科学基金(51661135024)资助。

摘　　要：量子反常霍尔效应是一种不需要外加磁场的量子霍尔效应.它不但为手征量子霍尔态的理解和应用提供了一个理想的研究平台,还可以用于构建多种新奇拓扑量子物态.本文回顾了近年来量子反常霍尔效应实验方面的研究进展,包括对磁性掺杂拓扑绝缘体中量子反常霍尔效应相关机理的深入研究、基于量子反常霍尔绝缘体的各种异质结构的制备及性质研究,以及可能具有更高工作温度的量子反常霍尔效应材料体系的探索等.这些研究进展对量子反常霍尔效应的未来发展方向和凝聚态物理的发展具有重要的启示作用.The quantum anomalous Hall(QAH)effect is a quantum Hall effect that can occur without external magnetic field.The experimental realization of this effect in magnetically doped topological insulator thin films not only provides an ideal platform for research and application on chiral quantum Hall state,but also paves the way for constructing many other exotic topological quantum phases.But the realization temperature of QAH is quite low.The non-uniform magnetic disorder could be one of main reasons.To increase the uniformity of magnetic order,different element was doped,like V instead of Cr,or Cr-V co-doping,which enhance the magnetic anisotropy in the system.In Cr-V co-doping system,the realization temperature of the QAH was ten times enhanced.Also,a penta-layer structure with heavily doped sub-surface layer was formed to effectively increase the QAH temperature.In this structure,the modulation-doping originates from the suppression of the disorder in the surface state interacting with the rich magnetic moments.In the future,with combined element doping and modified structure,we may get much improved QAH temperature.To elevate the working temperature of the QAH effect,a TI sandwiched by two ferromagnetic insulator layers is also applied because of the more ordered structure and potentially high Curie temperature.Although several works on FMI/TI heterostructure reports the proximity ferromagnetic in TI,the QAH was observed at quite a low temperature in an all-telluride base heterostructure.A strong coupling between the surface state of TI and ferromagnetic layer could be required.In a magnetically doped TI system,it is natural to ask how a QAH system evolves in a magnetization reversal process.Two groups observed the zero plateau of Hall conductance around the coercive field independently,indicating transition between two QAH phases occurs via an ordinary insulator phase,which could be understood in a multi-magnetic domain structure.A similar zero plateau of Hall conductance have been observed in magnetic-doped TI

关 键 词：量子反常霍尔效应 拓扑绝缘体 磁性掺杂 异质结构 内禀磁性 

分 类 号：O413[理学—理论物理] O469[理学—物理]