中国物理B ›› 2015, Vol. 24 ›› Issue (8): 87503-087503.doi: 10.1088/1674-1056/24/8/087503

• SPECIAL TOPIC—Silicene • 上一篇    下一篇

Antiferromagnetic and topological states in silicene: A mean field study

刘峰a b, 刘铖铖b, 姚裕贵b   

  1. a State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China;
    b School of Physics, Beijing Institute of Technology, Beijing 100081, China
  • 收稿日期:2015-06-05 修回日期:2015-06-29 出版日期:2015-08-05 发布日期:2015-08-05
  • 基金资助:
    Project supported by the National Key Basic Research Program of China (Grant Nos. 2014CB920903, 2013CB921903, 2011CBA00108, and 2012CB937500), the National Natural Science Foundation of China (Grant Nos. 11021262, 11172303, 11404022, 11225418, and 11174337), the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20121101110046), the Excellent Young Scholars Research Fund of Beijing Institute of Technology (Grant No. 2014CX04028), and the Basic Research Funds of Beijing Institute of Technology (Grant No. 20141842001).

Antiferromagnetic and topological states in silicene: A mean field study

Liu Feng (刘峰)a b, Liu Cheng-Cheng (刘铖铖)b, Yao Yu-Gui (姚裕贵)b   

  1. a State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China;
    b School of Physics, Beijing Institute of Technology, Beijing 100081, China
  • Received:2015-06-05 Revised:2015-06-29 Online:2015-08-05 Published:2015-08-05
  • Contact: Yao Yu-Gui E-mail:ygyao@bit.edu.cn
  • Supported by:
    Project supported by the National Key Basic Research Program of China (Grant Nos. 2014CB920903, 2013CB921903, 2011CBA00108, and 2012CB937500), the National Natural Science Foundation of China (Grant Nos. 11021262, 11172303, 11404022, 11225418, and 11174337), the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20121101110046), the Excellent Young Scholars Research Fund of Beijing Institute of Technology (Grant No. 2014CX04028), and the Basic Research Funds of Beijing Institute of Technology (Grant No. 20141842001).

摘要: It has been widely accepted that silicene is a topological insulator, and its gap closes first and then opens again with increasing electric field, which indicates a topological phase transition from the quantum spin Hall state to the band insulator state. However, due to the relatively large atomic spacing of silicene, which reduces the bandwidth, the electron–electron interaction in this system is considerably strong and cannot be ignored. The Hubbard interaction, intrinsic spin orbital coupling (SOC), and electric field are taken into consideration in our tight-binding model, with which the phase diagram of silicene is carefully investigated on the mean field level. We have found that when the magnitudes of the two mass terms produced by the Hubbard interaction and electric potential are close to each other, the intrinsic SOC flips the sign of the mass term at either K or K' for one spin and leads to the emergence of the spin-polarized quantum anomalous Hall state.

关键词: spin-polarized quantum anomalous Hall state, silicene, antiferromagnetic state

Abstract: It has been widely accepted that silicene is a topological insulator, and its gap closes first and then opens again with increasing electric field, which indicates a topological phase transition from the quantum spin Hall state to the band insulator state. However, due to the relatively large atomic spacing of silicene, which reduces the bandwidth, the electron–electron interaction in this system is considerably strong and cannot be ignored. The Hubbard interaction, intrinsic spin orbital coupling (SOC), and electric field are taken into consideration in our tight-binding model, with which the phase diagram of silicene is carefully investigated on the mean field level. We have found that when the magnitudes of the two mass terms produced by the Hubbard interaction and electric potential are close to each other, the intrinsic SOC flips the sign of the mass term at either K or K' for one spin and leads to the emergence of the spin-polarized quantum anomalous Hall state.

Key words: spin-polarized quantum anomalous Hall state, silicene, antiferromagnetic state

中图分类号:  (Magnetic properties of nanostructures)

  • 75.75.-c
73.43.-f (Quantum Hall effects) 71.70.Ej (Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect) 73.22.-f (Electronic structure of nanoscale materials and related systems)