中国物理B ›› 2025, Vol. 34 ›› Issue (6): 67401-067401.doi: 10.1088/1674-1056/adc7f4

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Strongly tunable Ising superconductivity in van der Waals NbSe2-xTex nanosheets

Jingyuan Qu(曲静远)1,2, Guojing Hu(胡国静)2,3,†, Cuili Xiang(向翠丽)1,‡, Hui Guo(郭辉)2,3, Senhao Lv(吕森浩)2,3, Yechao Han(韩烨超)2,3, Guoyu Xian(冼国裕)2,3, Qi Qi(齐琦)2,3, Zhen Zhao(赵振)2,3, Ke Zhu(祝轲)2,3, Xiao Lin(林晓)3, Lihong Bao(鲍丽宏)2,3, Yongjin Zou(邹勇进)1, Lixian Sun(孙立贤)1, Haitao Yang(杨海涛)2,3, and Hong-Jun Gao(高鸿钧)2,3   

  1. 1 Guangxi Key Laboratory of Information Materials, Guilin University of Electronic Technology, Guilin 541004, China;
    2 Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    3 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
  • 收稿日期:2025-02-18 修回日期:2025-03-28 接受日期:2025-04-02 出版日期:2025-05-16 发布日期:2025-06-11
  • 通讯作者: Guojing Hu, Cuili Xiang E-mail:gjhu@iphy.ac.cn;xiangcuili@guet.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 62488201 and 1240041502), the China Postdoctoral Science Foundation (Grant No. 2024T170990), the National Key R&D Program of China (Grant No. 2022YFA1204100), the Chinese Academy of Sciences (Grant No. XDB33030100), and the Innovation Program of Quantum Science and Technology (Grant No. 2021ZD0302700).

Strongly tunable Ising superconductivity in van der Waals NbSe2-xTex nanosheets

Jingyuan Qu(曲静远)1,2, Guojing Hu(胡国静)2,3,†, Cuili Xiang(向翠丽)1,‡, Hui Guo(郭辉)2,3, Senhao Lv(吕森浩)2,3, Yechao Han(韩烨超)2,3, Guoyu Xian(冼国裕)2,3, Qi Qi(齐琦)2,3, Zhen Zhao(赵振)2,3, Ke Zhu(祝轲)2,3, Xiao Lin(林晓)3, Lihong Bao(鲍丽宏)2,3, Yongjin Zou(邹勇进)1, Lixian Sun(孙立贤)1, Haitao Yang(杨海涛)2,3, and Hong-Jun Gao(高鸿钧)2,3   

  1. 1 Guangxi Key Laboratory of Information Materials, Guilin University of Electronic Technology, Guilin 541004, China;
    2 Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    3 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
  • Received:2025-02-18 Revised:2025-03-28 Accepted:2025-04-02 Online:2025-05-16 Published:2025-06-11
  • Contact: Guojing Hu, Cuili Xiang E-mail:gjhu@iphy.ac.cn;xiangcuili@guet.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 62488201 and 1240041502), the China Postdoctoral Science Foundation (Grant No. 2024T170990), the National Key R&D Program of China (Grant No. 2022YFA1204100), the Chinese Academy of Sciences (Grant No. XDB33030100), and the Innovation Program of Quantum Science and Technology (Grant No. 2021ZD0302700).

摘要: Ising superconductivity, induced by the strong spin-orbit coupling (SOC) and inversion symmetry breaking, can lead to the in-plane upper critical field exceeding the Pauli limit and hold significant potential for advancing the study of topological superconductivity. However, the enhancement of Ising superconductivity is still a challenging problem, important for engineering Majorana fermions and exploring topological quantum computing. In this study, we investigated the superconducting properties of a series of van der Waals NbSe$_{2-x}$Te$_{x}$ nanosheets. The Ising superconductivity in NbSe$_{2-x}$Te$_{x}$ nanosheets can be significantly enhanced by the substitution of Te, an element with strong SOC. The fitted in-plane upper critical field of NbSe$_{1.5}$Te$_{0.5}$ nanosheets at absolute zero temperature reaches up to 3.2 times the Pauli limit. Angular dependence of magnetoresistance measurements reveals a distinct two-fold rotational symmetry in the superconducting transition region, highlighting the role of strong SOC. In addition, the fitting results of the Berezinskii-Kosterlitz-Thouless (BKT) transition and the two-dimensional (2D) Tinkham formula provide strong evidence for 2D superconductivity. These findings offer new perspectives for the design and modulation of the Ising superconducting state and pave the way for their potential applications in topological superconductivity and quantum technologies.

关键词: Ising superconductivity, NbSe$_{2-x}$Te$_{x}$, spin-orbit coupling, upper critical field, Pauli limit

Abstract: Ising superconductivity, induced by the strong spin-orbit coupling (SOC) and inversion symmetry breaking, can lead to the in-plane upper critical field exceeding the Pauli limit and hold significant potential for advancing the study of topological superconductivity. However, the enhancement of Ising superconductivity is still a challenging problem, important for engineering Majorana fermions and exploring topological quantum computing. In this study, we investigated the superconducting properties of a series of van der Waals NbSe$_{2-x}$Te$_{x}$ nanosheets. The Ising superconductivity in NbSe$_{2-x}$Te$_{x}$ nanosheets can be significantly enhanced by the substitution of Te, an element with strong SOC. The fitted in-plane upper critical field of NbSe$_{1.5}$Te$_{0.5}$ nanosheets at absolute zero temperature reaches up to 3.2 times the Pauli limit. Angular dependence of magnetoresistance measurements reveals a distinct two-fold rotational symmetry in the superconducting transition region, highlighting the role of strong SOC. In addition, the fitting results of the Berezinskii-Kosterlitz-Thouless (BKT) transition and the two-dimensional (2D) Tinkham formula provide strong evidence for 2D superconductivity. These findings offer new perspectives for the design and modulation of the Ising superconducting state and pave the way for their potential applications in topological superconductivity and quantum technologies.

Key words: Ising superconductivity, NbSe$_{2-x}$Te$_{x}$, spin-orbit coupling, upper critical field, Pauli limit

中图分类号:  (Properties of superconductors)

  • 74.25.-q
74.25.F- (Transport properties)