1. Observation of superconducting diode effect in antiferromagnetic Mott insulator $\alpha$-RuCl$_3$
- Author
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He, Jiadian, Ding, Yifan, Zeng, Xiaohui, Zhang, Yiwen, Wang, Yanjiang, Dong, Peng, Zhou, Xiang, Wu, Yueshen, Cao, Kecheng, Ran, Kejing, Wang, Jinghui, Chen, Yulin, Watanabe, Kenji, Taniguchi, Takashi, Yu, Shun-Li, Li, Jian-Xin, Wen, Jinsheng, and Li, Jun
- Subjects
Condensed Matter - Superconductivity ,Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
Nonreciprocal superconductivity, also called as superconducting diode effect that spontaneously breaks time-reversal symmetry, is characterized by asymmetric critical currents under opposite applied current directions. This distinct state unveils a rich ore of intriguing physical properties, particularly in the realm of nanoscience application of superconductors. Towards the experimental realization of superconducting diode effect, the construction of two-dimensional heterostructures of magnets and $s$-wave superconductors is considered to be a promising pathway. In this study, we present our findings of superconducting diode effect manifested in the magnetic Mott insulator $\alpha$-RuCl$_3$. This phenomenon is induced by the proximity effect within a van der Waals heterostructure, consisting of thin $\alpha$-RuCl$_3$/NbSe$_2$ flakes. Through transport property measurements, we have confirmed a weak superconducting gap of 0.2 meV, which is significantly lower than the intrinsic gap of NbSe$_2$(1.2 meV). Upon the application of a weak magnetic field below 70 mT, we observed an asymmetry in the critical currents under positive and negative applied currents. This observation demonstrates a typical superconducting diode effect in the superconducting $\alpha$-RuCl$_3$. The superconducting diode effect and nonreciprocal resistance are observed exclusively when the magnetic field is aligned out-of-plane. This suggests that an Ising-type spin-orbit coupling in the superconducting $\alpha$-RuCl$_3$ may be responsible for the mechanism. Our findings furnish a platform for the exploration of superconducting diode effect via the artificial construction of heterostructures.
- Published
- 2024