中国物理B ›› 2024, Vol. 33 ›› Issue (7): 77202-077202.doi: 10.1088/1674-1056/ad498a

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Effect of the mixing of s-wave and chiral p-wave pairings on electrical shot noise properties of normal metal/superconductor tunnel junctions

Yu-Chen Hu(胡雨辰) and Liang-Bin Hu(胡梁宾)†   

  1. Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics, South China Normal University, Guangzhou 510631, China
  • 收稿日期:2023-12-28 修回日期:2024-04-20 接受日期:2024-05-10 出版日期:2024-06-18 发布日期:2024-07-05
  • 通讯作者: Liang-Bin Hu E-mail:lbhu26@126.com

Effect of the mixing of s-wave and chiral p-wave pairings on electrical shot noise properties of normal metal/superconductor tunnel junctions

Yu-Chen Hu(胡雨辰) and Liang-Bin Hu(胡梁宾)†   

  1. Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics, South China Normal University, Guangzhou 510631, China
  • Received:2023-12-28 Revised:2024-04-20 Accepted:2024-05-10 Online:2024-06-18 Published:2024-07-05
  • Contact: Liang-Bin Hu E-mail:lbhu26@126.com

摘要: We study theoretically the electrical shot noise properties of tunnel junctions between a normal metal and a superconductor with the mixture of singlet s-wave and chiral triplet p-wave pairing due to broken inversion symmetry. We investigate how the shot noise properties vary as the relative amplitude between the two parity components in the pairing potential is changed. It is demonstrated that some characteristics of the electrical shot noise properties of such tunnel junctions may depend sensitively on the relative amplitude between the two parity components in the pairing potential, and some significant changes may occur in the electrical shot noise properties when the relative amplitude between the two parity components is varied from the singlet s-wave pairing dominated regime to the chiral triplet p-wave pairing dominated regime. In the chiral triplet p-wave pairing dominated regime, the ratio of noise power to electric current is close to $2e$ both in the in-gap and in the out-gap region. In the singlet s-wave pairing dominated regime, the value of this ratio is close to $4e$ in the inner gap region but may reduce to about $2e$ in the outer gap region as the relative amplitude of the chiral triplet pairing component is increased. The variations of the differential shot noise with the bias voltage also exhibit some significantly different features in different regimes. Such different features can serve as useful diagnostic tools for the determination of the relative magnitude of the two parity components in the pairing potential.

关键词: normal metal/superconductor tunnel junctions, shot noise, mixing of s-wave and chiral p-wave pairing, spin-orbit coupling

Abstract: We study theoretically the electrical shot noise properties of tunnel junctions between a normal metal and a superconductor with the mixture of singlet s-wave and chiral triplet p-wave pairing due to broken inversion symmetry. We investigate how the shot noise properties vary as the relative amplitude between the two parity components in the pairing potential is changed. It is demonstrated that some characteristics of the electrical shot noise properties of such tunnel junctions may depend sensitively on the relative amplitude between the two parity components in the pairing potential, and some significant changes may occur in the electrical shot noise properties when the relative amplitude between the two parity components is varied from the singlet s-wave pairing dominated regime to the chiral triplet p-wave pairing dominated regime. In the chiral triplet p-wave pairing dominated regime, the ratio of noise power to electric current is close to $2e$ both in the in-gap and in the out-gap region. In the singlet s-wave pairing dominated regime, the value of this ratio is close to $4e$ in the inner gap region but may reduce to about $2e$ in the outer gap region as the relative amplitude of the chiral triplet pairing component is increased. The variations of the differential shot noise with the bias voltage also exhibit some significantly different features in different regimes. Such different features can serve as useful diagnostic tools for the determination of the relative magnitude of the two parity components in the pairing potential.

Key words: normal metal/superconductor tunnel junctions, shot noise, mixing of s-wave and chiral p-wave pairing, spin-orbit coupling

中图分类号:  (General formulation of transport theory)

  • 72.10.Bg
72.25.Dc (Spin polarized transport in semiconductors) 72.25.Ba (Spin polarized transport in metals) 72.15.-v (Electronic conduction in metals and alloys)