中国物理B ›› 2021, Vol. 30 ›› Issue (10): 100302-100302.doi: 10.1088/1674-1056/abff1c

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Detection of spin current through a quantum dot with Majorana bound states

Ning Wang(王宁), Xingtao An(安兴涛), and Shuhui Lv(吕树慧)   

  1. School of Sciences, Hebei University of Science and Technology, Shijiazhuang 050018, China
  • 收稿日期:2020-12-23 修回日期:2021-04-19 接受日期:2021-05-08 出版日期:2021-09-17 发布日期:2021-09-17
  • 通讯作者: Shuhui Lv E-mail:vshuhui@hebust.edu.cn
  • 基金资助:
    Project supported by Natural Science Fund for Colleges and Universities in Hebei Province, China (Grant No. ZD2017031) and the Doctoral Initial Funding of Hebei University of Science and Technology (Grant No. 1181291).

Detection of spin current through a quantum dot with Majorana bound states

Ning Wang(王宁), Xingtao An(安兴涛), and Shuhui Lv(吕树慧)   

  1. School of Sciences, Hebei University of Science and Technology, Shijiazhuang 050018, China
  • Received:2020-12-23 Revised:2021-04-19 Accepted:2021-05-08 Online:2021-09-17 Published:2021-09-17
  • Contact: Shuhui Lv E-mail:vshuhui@hebust.edu.cn
  • Supported by:
    Project supported by Natural Science Fund for Colleges and Universities in Hebei Province, China (Grant No. ZD2017031) and the Doctoral Initial Funding of Hebei University of Science and Technology (Grant No. 1181291).

摘要: The spin transport properties are theoretically investigated when a quantum dot (QD) is side-coupled to Majorana bound states (MBSs) driven by a symmetric dipolar spin battery. It is found that MBSs have a great effect on spin transport properties. The peak-to-valley ratio of the spin current decreases as the coupling strength between the MBS and the QD increases. Moreover, a non-zero charge current with two resonance peaks appears in the system. In the extreme case where the dot-MBS coupling strength is strong enough, the spin current and the charge current are both constants in the non-resonance peak range. When considering the effect of the Zeeman energy, it is interesting that the resonance peak at the higher energy appears one shoulder. And the shoulder turns into a peak when the Zeeman energy is big enough. In addition, the coupling strength between the two MBSs weakens their effects on the currents of the system. These results are helpful for understanding the MBSs signature in the transport spectra.

关键词: Majorana bound states, quantum dot, spin current, Green's function

Abstract: The spin transport properties are theoretically investigated when a quantum dot (QD) is side-coupled to Majorana bound states (MBSs) driven by a symmetric dipolar spin battery. It is found that MBSs have a great effect on spin transport properties. The peak-to-valley ratio of the spin current decreases as the coupling strength between the MBS and the QD increases. Moreover, a non-zero charge current with two resonance peaks appears in the system. In the extreme case where the dot-MBS coupling strength is strong enough, the spin current and the charge current are both constants in the non-resonance peak range. When considering the effect of the Zeeman energy, it is interesting that the resonance peak at the higher energy appears one shoulder. And the shoulder turns into a peak when the Zeeman energy is big enough. In addition, the coupling strength between the two MBSs weakens their effects on the currents of the system. These results are helpful for understanding the MBSs signature in the transport spectra.

Key words: Majorana bound states, quantum dot, spin current, Green's function

中图分类号:  (Quantum computation architectures and implementations)

  • 03.67.Lx
73.63.Kv (Quantum dots) 73.23.-b (Electronic transport in mesoscopic systems) 74.78.Na (Mesoscopic and nanoscale systems)