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中国科学院大学学报 ›› 2020, Vol. 37 ›› Issue (6): 736-743.DOI: 10.7523/j.issn.2095-6134.2020.06.003

• 数学与物理学 • 上一篇    下一篇

单层VCl3和VBr3中相互作用导致的量子反常霍尔绝缘体到莫特绝缘体相变

徐永峰1, 胜献雷2, 郑庆荣1   

  1. 1. 中国科学院大学物理科学学院, 北京 100049;
    2. 北京航空航天大学物理系 微纳测控与低维物理教育部重点实验室, 北京 100191
  • 收稿日期:2019-03-26 修回日期:2019-05-08 发布日期:2020-11-15
  • 通讯作者: 胜献雷, 郑庆荣
  • 基金资助:
    Supported by the National Natural Science Foundation of China(11574309,11504013)

Correlation-driven topological phase transition from quantum anomalous Hall insulator to Mott insulator in monolayer VCl3 and VBr3

XU Yongfeng1, SHENG Xianlei2, ZHENG Qingrong1   

  1. 1 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China;
    2 Key Laboratory of Micro-Nano Measurement-Manipulation and Physics of Ministry of Education, Department of Physics, Beihang University, Beijing 100191, China
  • Received:2019-03-26 Revised:2019-05-08 Published:2020-11-15
  • Supported by:
    Supported by the National Natural Science Foundation of China(11574309,11504013)

摘要: 基于第一性原理计算,发现在不考虑3d电子间关联作用的情况下,二维单层材料VCl3和VBr3是面内铁磁半导体,并且具有量子反常霍尔效应。VCl3能隙约为3.4 meV,VBr3没有全局的能隙。有趣的是,VCl3的陈数为3,有3个手性边缘态;VBr3的陈数为1,对应1个手性边缘态。当考虑关联作用U后,它们会变为Mott绝缘体。对于VCl3,相变点发生在U=0.45 eV;对于VBr3,相变点发生在U=0.35 eV。

关键词: 铁磁半导体, 大陈数, Mott绝缘体

Abstract: Based on the first-principle calculations, we propose that the monolayer VCl3 and VBr3 are quantum anomalous Hall insulators with in-plane magnetization without considering the correlation effect of the 3d electron-electron interaction. The band gap is predicted to be about 3.4 meV for VCl3, but no global gap for VBr3. It is interesting to note that VCl3 (VBr3) possesses a Chern number of C=3 (C=1) with three (one) chiral edge states. After considering correlation effect, we obtain Mott insulator if U>0.45 (U>0.35) eV for VCl3 (VBr3).

Key words: ferromagnetic semiconductor, large Chern number, Mott insulator

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