中国物理B ›› 2013, Vol. 22 ›› Issue (3): 37304-037304.doi: 10.1088/1674-1056/22/3/037304

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

Wave-vector filtering effect of electric–magnetic barrier in HgTe quantum wells

邹永连a, 宋俊涛b   

  1. a Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    b Department of Physics and Hebei Advanced Thin Film Laboratory, Hebei Normal University, Shijiazhuang 050024, China
  • 收稿日期:2012-10-18 修回日期:2012-12-12 出版日期:2013-02-01 发布日期:2013-02-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 10821403 and 11047131), the National Basic Research Program of China (Grant No. 2009CB929100), and the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20101303120005).

Wave-vector filtering effect of electric–magnetic barrier in HgTe quantum wells

Zou Yong-Lian (邹永连)a, Song Jun-Tao (宋俊涛)b   

  1. a Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    b Department of Physics and Hebei Advanced Thin Film Laboratory, Hebei Normal University, Shijiazhuang 050024, China
  • Received:2012-10-18 Revised:2012-12-12 Online:2013-02-01 Published:2013-02-01
  • Contact: Song Jun-Tao E-mail:juntaosong@foxmail.com
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 10821403 and 11047131), the National Basic Research Program of China (Grant No. 2009CB929100), and the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20101303120005).

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摘要： Because of helicity of electrons in HgTe quantum wells (QWs) with inverted band structure, the electrons cannot be confined by electric barriers since electrons can tunnel the barriers perfectly without backscattering in HgTe QWs. This behavior is similar to Dirac electrons in graphene. In this paper, we propose a scheme to confine carriers in HgTe QWs using an electric-magnetic barrier. We calculate the transmission of carriers in 2-dimensional HgTe QWs and find that the wave-vector filtering effect of local magnetic fields can confine the carriers. The confining effect will have potential application in nanodevices based on HgTe QWs.

关键词: magnetic barrier, topological insulator, helical states, HgTe quantum well

Abstract: Because of helicity of electrons in HgTe quantum wells (QWs) with inverted band structure, the electrons cannot be confined by electric barriers since electrons can tunnel the barriers perfectly without backscattering in HgTe QWs. This behavior is similar to Dirac electrons in graphene. In this paper, we propose a scheme to confine carriers in HgTe QWs using an electric–magnetic barrier. We calculate the transmission of carriers in 2-dimensional HgTe QWs and find that the wave-vector filtering effect of local magnetic fields can confine the carriers. The confining effect will have potential application in nanodevices based on HgTe QWs.

Key words: magnetic barrier, topological insulator, helical states, HgTe quantum well

中图分类号:  (Quantum wells)

  • 73.63.Hs
73.20.At (Surface states, band structure, electron density of states) 73.23.Ad (Ballistic transport) 73.40.Gk (Tunneling)