中国物理B ›› 2021, Vol. 30 ›› Issue (10): 106802-106802.doi: 10.1088/1674-1056/ac0903
Direct observation of the scaling relation between density of states and pairing gap in a dirty superconductor
Chang-Jiang Zhu(朱长江)1,2,†, Limin Liu(刘立民)1,2,†, Peng-Bo Song(宋鹏博)1,2,†, Han-Bin Deng(邓翰宾)1,2, Chang-Jiang Yi(伊长江)1, Ying-Kai Sun(孙英开)1,2, R Wu(武睿)1,5, Jia-Xin Yin(殷嘉鑫)4, Youguo Shi(石友国)1,‡, Ziqiang Wang(汪自强)6,§, and Shuheng H. Pan(潘庶亨)1,2,3,5,¶
- 1 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
2 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China;
3 CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China;
4 Laboratory for Topological Quantum Matter and Advanced Spectroscopy(B7), Department of Physics, Princeton University, Princeton, NJ, USA;
5 Songshan Lake Materials Laboratory, Dongguan 523808, China;
6 Department of Physics, Boston College, Chestnut Hill, MA, USA
Direct observation of the scaling relation between density of states and pairing gap in a dirty superconductor
Chang-Jiang Zhu(朱长江)1,2,†, Limin Liu(刘立民)1,2,†, Peng-Bo Song(宋鹏博)1,2,†, Han-Bin Deng(邓翰宾)1,2, Chang-Jiang Yi(伊长江)1, Ying-Kai Sun(孙英开)1,2, R Wu(武睿)1,5, Jia-Xin Yin(殷嘉鑫)4, Youguo Shi(石友国)1,‡, Ziqiang Wang(汪自强)6,§, and Shuheng H. Pan(潘庶亨)1,2,3,5,¶
- 1 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
2 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China;
3 CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China;
4 Laboratory for Topological Quantum Matter and Advanced Spectroscopy(B7), Department of Physics, Princeton University, Princeton, NJ, USA;
5 Songshan Lake Materials Laboratory, Dongguan 523808, China;
6 Department of Physics, Boston College, Chestnut Hill, MA, USA
摘要： Theories and experiments on dirty superconductors are complex but important in terms of both theoretical fundamentals and practical applications. These activities are even more challenging when magnetic fields are present because the field distribution, electron density of states, and superconducting pairing potentials become nonuniform. Here, we present tunneling microspectroscopic experiments on NbC single crystals and demonstrate that NbC is a homogeneous dirty superconductor. When applying magnetic fields to the samples, we found that the zero-energy local density of states and the pairing energy gap followed the explicit scaling relation proposed by de Gennes for homogeneous dirty superconductors in high magnetic fields. More significantly, our experimental findings indicate that the validity of the scaling relation extends to magnetic field strengths far below the upper critical field, calling for a new nonperturbative understanding of this fundamental property in dirty superconductors. On the practical side, we used the observed scaling relation to derive a simple and straightforward experimental scheme for estimating the superconducting coherence length of a dirty superconductor in magnetic fields.
中图分类号: (Scanning tunneling microscopy (including chemistry induced with STM))
- 68.37.Ef