›› 2014, Vol. 23 ›› Issue (7): 77302-077302.doi: 10.1088/1674-1056/23/7/077302

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Efficiency of electrical manipulation in two-dimensional topological insulators

庞蜜, 吴晓光   

  1. SKLSM, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
  • 收稿日期:2013-12-14 修回日期:2014-01-22 出版日期:2014-07-15 发布日期:2014-07-15
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61076092 and 61290303).

Efficiency of electrical manipulation in two-dimensional topological insulators

Pang Mi (庞蜜), Wu Xiao-Guang (吴晓光)   

  1. SKLSM, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
  • Received:2013-12-14 Revised:2014-01-22 Online:2014-07-15 Published:2014-07-15
  • Contact: Pang Mi E-mail:pangmi@semi.ac.cn
  • About author:73.21.Cd; 73.22.Dj
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61076092 and 61290303).

摘要: We investigate the efficiency of electrical manipulation in a two-dimensional topological insulator by inspecting the electronic states of a lateral electrical potential superlattice in the system. The spatial distribution of the electron density in the system can be tuned by changing the strength of the externally applied lateral electrical superlattice potential. This provides us the information about how efficiently one can manipulate the electron motion inside a two-dimensional topological insulator. Such information is important in designing electronic devices, e.g., an electric field effect transistor made of the topological insulator. The electronic states under various conditions are examined carefully. It is found that the dispersion of the mini-band and the electron distribution in the potential well region both display an oscillatory behavior as the potential strength of the lateral superlattice increases. The probability of finding an electron in the potential well region can be larger or smaller than the average as the potential strength varies. These features can be attributed to the coupled multiple-band nature of the topological insulator. In addition, it is also found that these behaviors are not sensitive to the gap parameter of the two-dimensional topological insulator model. Our study suggests that the electron density manipulation via electrical gating in a two-dimensional topological insulator is less effective and more delicate than that in a traditional single-band semiconductor.

关键词: topological insulator, lateral potential superlattice, electrical manipulation

Abstract: We investigate the efficiency of electrical manipulation in a two-dimensional topological insulator by inspecting the electronic states of a lateral electrical potential superlattice in the system. The spatial distribution of the electron density in the system can be tuned by changing the strength of the externally applied lateral electrical superlattice potential. This provides us the information about how efficiently one can manipulate the electron motion inside a two-dimensional topological insulator. Such information is important in designing electronic devices, e.g., an electric field effect transistor made of the topological insulator. The electronic states under various conditions are examined carefully. It is found that the dispersion of the mini-band and the electron distribution in the potential well region both display an oscillatory behavior as the potential strength of the lateral superlattice increases. The probability of finding an electron in the potential well region can be larger or smaller than the average as the potential strength varies. These features can be attributed to the coupled multiple-band nature of the topological insulator. In addition, it is also found that these behaviors are not sensitive to the gap parameter of the two-dimensional topological insulator model. Our study suggests that the electron density manipulation via electrical gating in a two-dimensional topological insulator is less effective and more delicate than that in a traditional single-band semiconductor.

Key words: topological insulator, lateral potential superlattice, electrical manipulation

中图分类号:  (Superlattices)

  • 73.21.Cd
73.22.Dj (Single particle states)