中国物理B ›› 2001, Vol. 10 ›› Issue (13): 4-9.

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RESONANT ANDREEV REFLECTION IN HYBRID SUPERCONDUCTING-NORMAL NANOSTRUTURES

林宗涵   

  1. State Key Laboratory for Mesoscopic Physics Department of Physics, Peking University, Beijing 100871, China
  • 收稿日期:2001-02-11 出版日期:2001-12-25 发布日期:2005-07-07
  • 基金资助:
    Project supported by the Visiting Scholar Foundation of Key State Laboratory for Mesoscopic Physics in Peking University and by National Natural Science Foundation of China (Grant No.10074001).

RESONANT ANDREEV REFLECTION IN HYBRID SUPERCONDUCTING-NORMAL NANOSTRUTURES

Lin Tsung-han (林宗涵)   

  1. State Key Laboratory for Mesoscopic Physics Department of Physics, Peking University, Beijing 100871, China
  • Received:2001-02-11 Online:2001-12-25 Published:2005-07-07
  • Supported by:
    Project supported by the Visiting Scholar Foundation of Key State Laboratory for Mesoscopic Physics in Peking University and by National Natural Science Foundation of China (Grant No.10074001).

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摘要： After a brief description of hybrid superconducting-normal nanostructures and a brief introduction of the Andreev reflection, we present a theoretical investigation of the electron tunneling through a normal-metal/quantum-dot/superconductor (N-QD-S) system where multiple discrete levels of the QD is considered. By using the nonequilibrium-Green-function (NGF) method, the current I is obtained and studied in detail. We find that the Andreev tunneling shows clear resonant behavior, as obtained in previous works. Moreover, the current I versus the gate voltage Vg exhibits different kinds of peaks, depending on the bias voltage, the level-spacing of the QD, and the energy gap of the superconducting electrode. Besides, in I-V characteristics extra peaks superimposed on the conventional current plateaus emerge, which stem from the resonant Andreev reflections.

Abstract: After a brief description of hybrid superconducting-normal nanostructures and a brief introduction of the Andreev reflection, we present a theoretical investigation of the electron tunneling through a normal-metal/quantum-dot/superconductor (N-QD-S) system where multiple discrete levels of the QD is considered. By using the nonequilibrium-Green-function (NGF) method, the current I is obtained and studied in detail. We find that the Andreev tunneling shows clear resonant behavior, as obtained in previous works. Moreover, the current I versus the gate voltage Vg exhibits different kinds of peaks, depending on the bias voltage, the level-spacing of the QD, and the energy gap of the superconducting electrode. Besides, in I-V characteristics extra peaks superimposed on the conventional current plateaus emerge, which stem from the resonant Andreev reflections.

Key words: transport properties, tunneling phenomena

中图分类号: 

  • 7430F