中国物理B ›› 2016, Vol. 25 ›› Issue (3): 37304-037304.doi: 10.1088/1674-1056/25/3/037304

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

Resonant Andreev reflection in a normal-metal/quantum-dot/superconductor system with coupled Majorana bound states

Su-Xin Wang(王素新), Yu-Xian Li(李玉现), Jian-Jun Liu(刘建军)   

  1. 1. College of Physical Science and Information Engineering and Hebei Advanced Thin Film Laboratory, Hebei Normal University, Shijiazhuang 050024, China;
    2. Department of Physics, Hebei Normal University for Nationalities, Chengde 067000, China;
    3. Physics Department, Shijiazhuang University, Shijiazhuang 050035, China
  • 收稿日期:2015-10-09 修回日期:2015-12-03 出版日期:2016-03-05 发布日期:2016-03-05
  • 通讯作者: Jian-Jun Liu E-mail:liujj@mail.hebtu.edu.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 61176089 and 10974043), the Natural Science Foundation of Hebei Province, China (Grant Nos. A2011205092 and 2014205005), and the Fund for Hebei Normal University for Nationalities, China (Grant No. 201109).

Resonant Andreev reflection in a normal-metal/quantum-dot/superconductor system with coupled Majorana bound states

Su-Xin Wang(王素新)1,2, Yu-Xian Li(李玉现)1, Jian-Jun Liu(刘建军)1,3   

  1. 1. College of Physical Science and Information Engineering and Hebei Advanced Thin Film Laboratory, Hebei Normal University, Shijiazhuang 050024, China;
    2. Department of Physics, Hebei Normal University for Nationalities, Chengde 067000, China;
    3. Physics Department, Shijiazhuang University, Shijiazhuang 050035, China
  • Received:2015-10-09 Revised:2015-12-03 Online:2016-03-05 Published:2016-03-05
  • Contact: Jian-Jun Liu E-mail:liujj@mail.hebtu.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 61176089 and 10974043), the Natural Science Foundation of Hebei Province, China (Grant Nos. A2011205092 and 2014205005), and the Fund for Hebei Normal University for Nationalities, China (Grant No. 201109).

摘要:

Andreev reflection (AR) in a normal-metal/quantum-dot/superconductor (N-QD-S) system with coupled Majorana bound states (MBSs) is investigated theoretically. We find that in the N-QD-S system, the AR can be enhanced when coupling to the MBSs is incorporated. Fano line-shapes can be observed in the AR conductance spectrum when there is an appropriate QD-MBS coupling or MBS-MBS coupling. The AR conductance is always e2/2h at the zero Fermi energy point when only QD-MBSs coupling is considered. In addition, the resonant AR occurs when the MBS-MBS coupling roughly equals to the QD energy level. We also find that an AR antiresonance appears when the QD energy level approximately equals to the sum of the QD-MBS coupling and the MBS-MBS coupling. These features may serve as characteristic signatures for the probe of MBSs.

关键词: Majorana bound states, Andreev reflection, Fano effect, quantum dot

Abstract:

Andreev reflection (AR) in a normal-metal/quantum-dot/superconductor (N-QD-S) system with coupled Majorana bound states (MBSs) is investigated theoretically. We find that in the N-QD-S system, the AR can be enhanced when coupling to the MBSs is incorporated. Fano line-shapes can be observed in the AR conductance spectrum when there is an appropriate QD-MBS coupling or MBS-MBS coupling. The AR conductance is always e2/2h at the zero Fermi energy point when only QD-MBSs coupling is considered. In addition, the resonant AR occurs when the MBS-MBS coupling roughly equals to the QD energy level. We also find that an AR antiresonance appears when the QD energy level approximately equals to the sum of the QD-MBS coupling and the MBS-MBS coupling. These features may serve as characteristic signatures for the probe of MBSs.

Key words: Majorana bound states, Andreev reflection, Fano effect, quantum dot

中图分类号:  (Quantum dots)

  • 73.21.La
74.45.+c (Proximity effects; Andreev reflection; SN and SNS junctions) 73.23.Hk (Coulomb blockade; single-electron tunneling)