1. Evidence of P-wave Pairing in K2Cr3As3 Superconductors from Phase-sensitive Measurement
- Author
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Zhang, Zhiyuan, Dou, Ziwei, Wang, Anqi, Zhang, Cuiwei, Hong, Yu, Lei, Xincheng, Pan, Yue, Xu, Zhongchen, Xu, Zhipeng, Li, Yupeng, Li, Guoan, Shi, Xiaofan, Guo, Xingchen, Deng, Xiao, Lyu, Zhaozheng, Li, Peiling, Qu, Faming, Liu, Guangtong, Su, Dong, Jiang, Kun, Shi, Youguo, Lu, Li, Shen, Jie, and Hu, Jiangping
- Subjects
Condensed Matter - Superconductivity ,Condensed Matter - Mesoscale and Nanoscale Physics ,Quantum Physics - Abstract
P-wave superconductors hold immense promise for both fundamental physics and practical applications due to their unusual pairing symmetry and potential topological superconductivity. However, the exploration of the p-wave superconductors has proved to be a complex endeavor. Not only are they rare in nature but also the identification of p-wave superconductors has been an arduous task in history. For example, phase-sensitive measurement, an experimental technique which can provide conclusive evidence for unconventional pairing, has not been implemented successfully to identify p-wave superconductors. Here, we study a recently discovered family of superconductors, A2Cr3As3 (A = K, Rb, Cs), which were proposed theoretically to be a candidate of p-wave superconductors. We fabricate superconducting quantum interference devices (SQUIDs) on exfoliated K2Cr3As3, and perform the phase-sensitive measurement. We observe that such SQUIDs exhibit a pronounced second-order harmonic component sin(2{\phi}) in the current-phase relation, suggesting the admixture of 0- and {\pi}-phase. By carefully examining the magnetic field dependence of the oscillation patterns of critical current and Shapiro steps under microwave irradiation, we reveal a crossover from 0- to {\pi}-dominating phase state and conclude that the existence of the {\pi}-phase is in favor of the p-wave pairing symmetry in K2Cr3As3.
- Published
- 2024