中国物理B ›› 2018, Vol. 27 ›› Issue (10): 107401-107401.doi: 10.1088/1674-1056/27/10/107401

所属专题: TOPICAL REVIEW — Fundamental research under high magnetic fields

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

Superconductivity with peculiar upper critical fields in quasi-one-dimensional Cr-based pnictides

Guang-Han Cao(曹光旱), Zeng-Wei Zhu(朱增伟)   

  1. 1 Department of Physics, Zhejiang University, Hangzhou 310027, China;
    2 Wuhan National High Magnetic Field Center, School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
  • 收稿日期:2018-06-20 修回日期:2018-07-19 出版日期:2018-10-05 发布日期:2018-10-05
  • 通讯作者: Guang-Han Cao E-mail:ghcao@zju.edu.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 11674281 and 11574097) and the Fundamental Research Funds for the Central Universities of China.

Superconductivity with peculiar upper critical fields in quasi-one-dimensional Cr-based pnictides

Guang-Han Cao(曹光旱)1, Zeng-Wei Zhu(朱增伟)2   

  1. 1 Department of Physics, Zhejiang University, Hangzhou 310027, China;
    2 Wuhan National High Magnetic Field Center, School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
  • Received:2018-06-20 Revised:2018-07-19 Online:2018-10-05 Published:2018-10-05
  • Contact: Guang-Han Cao E-mail:ghcao@zju.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 11674281 and 11574097) and the Fundamental Research Funds for the Central Universities of China.

摘要:

The discovery of superconductivity in quasi-one-dimensional Cr-based pnictides A2Cr3As3 (A=alkali metals) has generated considerable research interest, primarily owing to their reduced dimensionality, significant electron correlations, and possible unconventional superconductivity. The upper critical field (Hc2) provides important information on the superconducting pairing. In this paper, we first briefly overview the latest research progress on the Cr-based superconductors. Then, we introduce typical Hc2(T) behaviors of type-Ⅱ superconductors in relation with the pair-breaking mechanisms. After a description of the measurement method for Hc2, we focus on the analysis of Hc2 data, especially for the temperature and angle dependence, in K2Cr3As3 crystals. The result indicates (i) an absence of Pauli-paramagnetic pair breaking for field perpendicular to the Cr3As3 chains, and (ii) a unique threefold modulation for the in-plane Hc2(φ) profile. Finally we conclude with remarks on the possible unconventional superconducting pairing symmetry.

关键词: Cr-based superconductors, upper critical fields, unconventional superconductivity

Abstract:

The discovery of superconductivity in quasi-one-dimensional Cr-based pnictides A2Cr3As3 (A=alkali metals) has generated considerable research interest, primarily owing to their reduced dimensionality, significant electron correlations, and possible unconventional superconductivity. The upper critical field (Hc2) provides important information on the superconducting pairing. In this paper, we first briefly overview the latest research progress on the Cr-based superconductors. Then, we introduce typical Hc2(T) behaviors of type-Ⅱ superconductors in relation with the pair-breaking mechanisms. After a description of the measurement method for Hc2, we focus on the analysis of Hc2 data, especially for the temperature and angle dependence, in K2Cr3As3 crystals. The result indicates (i) an absence of Pauli-paramagnetic pair breaking for field perpendicular to the Cr3As3 chains, and (ii) a unique threefold modulation for the in-plane Hc2(φ) profile. Finally we conclude with remarks on the possible unconventional superconducting pairing symmetry.

Key words: Cr-based superconductors, upper critical fields, unconventional superconductivity

中图分类号:  (Pnictides and chalcogenides)

  • 74.70.Xa
74.10.+v (Occurrence, potential candidates) 74.25.Op (Mixed states, critical fields, and surface sheaths)