Tunable dynamical magnetoelectric effect in antiferromagnetic topological insulator MnBi_(2)Te_(4) films  

作　　者：Tongshuai Zhu Huaiqiang Wang Haijun Zhang Dingyu Xing 

机构地区：[1]National Laboratory of Solid State Microstructures,School of Physics,Nanjing University,Nanjing,China [2]Department of Physics,University of Zurich,Zurich,Switzerland [3]Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing,China

出　　处：《npj Computational Materials》2021年第1期1101-1106,共6页计算材料学（英文）

基　　金：H.Z.acknowledge Jing Wang for helpful discussions.This work is supported by the Fundamental Research Funds for the Central Universities(Grant No.020414380185);Natural Science Foundation of Jiangsu Province(No.BK20200007);the Natural Science Foundation of China(Grants No.12074181 and No.11834006);the Fok Ying-Tong Education Foundation of China(Grant No.161006).

摘　　要：Axion was postulated as an elementary particle to solve the strong charge conjugation and parity puzzle,and later axion was also considered to be a possible component of dark matter in the universe.However,the existence of axions in nature has not been confirmed.Interestingly,axions arise out of pseudoscalar fields derived from the Chern–Simons theory in condensed matter physics.In antiferromagnetic insulators,the axion field can become dynamical due to spin-wave excitations and exhibits rich exotic phenomena,such as axion polariton.However,antiferromagnetic dynamical axion insulator has yet been experimentally identified in realistic materials.Very recently,MnBi_(2)Te_(4)was discovered to be an antiferromagnetic topological insulator with a quantized static axion field protected by inversion symmetry P and magnetic-crystalline symmetry S.Here,we studied MnBi_(2)Te_(4)films in which both the P and S symmetries are spontaneously broken and found that substantially enhanced dynamical magnetoelectric effects could be realized through tuning the thickness of MnBi_(2)Te_(4)films,temperature,or element substitutions.Our results show that thin films of MnBi_(2)Te_(4)and related compounds could provide a promising material platform to experimentally study axion electrodynamics.

关 键 词：materials DYNAMICAL INSULATOR 

分 类 号：TM21[一般工业技术—材料科学与工程]