中国物理B ›› 2024, Vol. 33 ›› Issue (12): 127301-127301.doi: 10.1088/1674-1056/ad84cb

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Strain-modulated antiferromagnetic Chern insulator in NiOsCl6 monolayer

Bin Wu(武斌)†, Na Li(李娜)†, Xin-Lian Chen(陈新莲), Wei-Xiao Ji(纪维霄), Pei-Ji Wang(王培吉), Shu-Feng Zhang(张树峰)‡, and Chang-Wen Zhang(张昌文)§   

  1. School of Physics and Technology, University of Jinan, Jinan 250022, China
  • 收稿日期:2024-07-26 修回日期:2024-10-01 接受日期:2024-10-09 出版日期:2024-12-15 发布日期:2024-12-15
  • 通讯作者: Shu-Feng Zhang, Chang-Wen Zhang E-mail:sps_zhangsf@ujn.edu.cn;ss_zhangchw@ujn.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 12104183, 52173283, and 62071200), the Natural Science Foundation of Shandong Province, China (Grant Nos. ZR2021MA040 and ZR2023MA091), the Taishan Scholar Program of Shandong Province, China (Grant No. ts20190939), and the Independent Cultivation Program of Innovation Team of Jinan City (Grant No. 2021GXRC043).

Strain-modulated antiferromagnetic Chern insulator in NiOsCl6 monolayer

Bin Wu(武斌)†, Na Li(李娜)†, Xin-Lian Chen(陈新莲), Wei-Xiao Ji(纪维霄), Pei-Ji Wang(王培吉), Shu-Feng Zhang(张树峰)‡, and Chang-Wen Zhang(张昌文)§   

  1. School of Physics and Technology, University of Jinan, Jinan 250022, China
  • Received:2024-07-26 Revised:2024-10-01 Accepted:2024-10-09 Online:2024-12-15 Published:2024-12-15
  • Contact: Shu-Feng Zhang, Chang-Wen Zhang E-mail:sps_zhangsf@ujn.edu.cn;ss_zhangchw@ujn.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 12104183, 52173283, and 62071200), the Natural Science Foundation of Shandong Province, China (Grant Nos. ZR2021MA040 and ZR2023MA091), the Taishan Scholar Program of Shandong Province, China (Grant No. ts20190939), and the Independent Cultivation Program of Innovation Team of Jinan City (Grant No. 2021GXRC043).

摘要: Recently, Chern insulators in an antiferromagnetic (AFM) phase have been suggested theoretically and predicted in a few materials. However, the experimental observation of two-dimensional (2D) AFM quantum anomalous Hall effect is still a challenge to date. In this work, we propose that an AFM Chern insulator can be realized in a 2D monolayer of NiOsCl$_6$ modulated by a compressive strain. Strain modulation is accessible experimentally and used widely in predicting and tuning topological nontrivial phases. With first-principles calculations, we have investigated the structural, magnetic, and electronic properties of NiOsCl$_6$. Its stability has been confirmed through molecular dynamical simulations, elasticity constant, and phonon spectrum. It has a collinear AFM order, with opposite magnetic moments of 1.3 $\mu_{\rm B}$ on each Ni/Os atom, respectively, and the Néel temperature is estimated to be 93 K. In the absence of strain, it functions as an AFM insulator with a direct gap with spin-orbital coupling included. Compressive strain will induce a transition from a normal insulator to a Chern insulator characterized by a Chern number $C = 1$, with a band gap of about 30 meV. This transition is accompanied by a structural distortion. Remarkably, the Chern insulator phase persists within the 3%-10% compressive strain range, offering an alternative platform for the utilization of AFM materials in spintronic devices.

关键词: Chern insulator, antiferromagnetism, topological materials

Abstract: Recently, Chern insulators in an antiferromagnetic (AFM) phase have been suggested theoretically and predicted in a few materials. However, the experimental observation of two-dimensional (2D) AFM quantum anomalous Hall effect is still a challenge to date. In this work, we propose that an AFM Chern insulator can be realized in a 2D monolayer of NiOsCl$_6$ modulated by a compressive strain. Strain modulation is accessible experimentally and used widely in predicting and tuning topological nontrivial phases. With first-principles calculations, we have investigated the structural, magnetic, and electronic properties of NiOsCl$_6$. Its stability has been confirmed through molecular dynamical simulations, elasticity constant, and phonon spectrum. It has a collinear AFM order, with opposite magnetic moments of 1.3 $\mu_{\rm B}$ on each Ni/Os atom, respectively, and the Néel temperature is estimated to be 93 K. In the absence of strain, it functions as an AFM insulator with a direct gap with spin-orbital coupling included. Compressive strain will induce a transition from a normal insulator to a Chern insulator characterized by a Chern number $C = 1$, with a band gap of about 30 meV. This transition is accompanied by a structural distortion. Remarkably, the Chern insulator phase persists within the 3%-10% compressive strain range, offering an alternative platform for the utilization of AFM materials in spintronic devices.

Key words: Chern insulator, antiferromagnetism, topological materials

中图分类号:  (Quantum Hall effects)

  • 73.43.-f
75.50.Ee (Antiferromagnetics) 71.15.Mb (Density functional theory, local density approximation, gradient and other corrections)