中国物理B ›› 2020, Vol. 29 ›› Issue (5): 57502-057502.doi: 10.1088/1674-1056/ab8209

所属专题: SPECIAL TOPIC — Topological 2D materials

• SPECIAL TOPIC—Recent advances in thermoelectric materials and devices • 上一篇    下一篇

Magnetic field enhanced single particle tunneling in MoS2-superconductor vertical Josephson junction

Wen-Zheng Xu(徐文正), Lai-Xiang Qin(秦来香), Xing-Guo Ye(叶兴国), Fang Lin(林芳), Da-Peng Yu(俞大鹏), Zhi-Min Liao(廖志敏)   

  1. 1 State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China;
    2 Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China;
    3 Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
  • 收稿日期:2020-01-14 修回日期:2020-02-11 出版日期:2020-05-05 发布日期:2020-05-05
  • 通讯作者: Zhi-Min Liao E-mail:liaozm@pku.edu.cn
  • 基金资助:
    Project supported by the National Key Research and Development Program of China (Grant Nos. 2018YFA0703703 and 2016YFA0300802) and the National Natural Science Foundation of China (Grant Nos. 91964201, 61825401, and 11774004).

Magnetic field enhanced single particle tunneling in MoS2-superconductor vertical Josephson junction

Wen-Zheng Xu(徐文正)1, Lai-Xiang Qin(秦来香)1, Xing-Guo Ye(叶兴国)1, Fang Lin(林芳)1, Da-Peng Yu(俞大鹏)2, Zhi-Min Liao(廖志敏)1,3   

  1. 1 State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China;
    2 Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China;
    3 Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
  • Received:2020-01-14 Revised:2020-02-11 Online:2020-05-05 Published:2020-05-05
  • Contact: Zhi-Min Liao E-mail:liaozm@pku.edu.cn
  • Supported by:
    Project supported by the National Key Research and Development Program of China (Grant Nos. 2018YFA0703703 and 2016YFA0300802) and the National Natural Science Foundation of China (Grant Nos. 91964201, 61825401, and 11774004).

摘要: As a prototypical transition-metal dichalcogenide semiconductor, MoS2 possesses strong spin-orbit coupling, which provides an ideal platform for the realization of interesting physical phenomena. Here, we report the magnetotransport properties in NbN-MoS2-NbN sandwich junctions at low temperatures. Above the critical temperature around ~11 K, the junction resistance shows weak temperature dependence, indicating a tunneling behavior. While below ~11 K, nearly zero junction resistance is observed, indicating the superconducting state in the MoS2 layer induced by the superconducting proximity effect. When a perpendicular magnetic field ~1 T is applied, such proximity effect is suppressed, accompanying with insulator-like temperature-dependence of the junction resistance. Intriguingly, when further increasing the magnetic field, the junction conductance is significantly enhanced, which is related to the enhanced single particle tunneling induced by the decrease of the superconducting energy gap with increasing magnetic fields. In addition, the possible Majorana zero mode on the surface of MoS2 can further lead to the enhancement of the junction conductance.

关键词: proximity effect, transition metal dichalcogenides, magnetotransport

Abstract: As a prototypical transition-metal dichalcogenide semiconductor, MoS2 possesses strong spin-orbit coupling, which provides an ideal platform for the realization of interesting physical phenomena. Here, we report the magnetotransport properties in NbN-MoS2-NbN sandwich junctions at low temperatures. Above the critical temperature around ~11 K, the junction resistance shows weak temperature dependence, indicating a tunneling behavior. While below ~11 K, nearly zero junction resistance is observed, indicating the superconducting state in the MoS2 layer induced by the superconducting proximity effect. When a perpendicular magnetic field ~1 T is applied, such proximity effect is suppressed, accompanying with insulator-like temperature-dependence of the junction resistance. Intriguingly, when further increasing the magnetic field, the junction conductance is significantly enhanced, which is related to the enhanced single particle tunneling induced by the decrease of the superconducting energy gap with increasing magnetic fields. In addition, the possible Majorana zero mode on the surface of MoS2 can further lead to the enhancement of the junction conductance.

Key words: proximity effect, transition metal dichalcogenides, magnetotransport

中图分类号:  (Proximity effects; Andreev reflection; SN and SNS junctions)

  • 74.45.+c
75.47.-m (Magnetotransport phenomena; materials for magnetotransport) 73.43.Qt (Magnetoresistance)