Ongoing advances in superconductors continue to revolutionize technology thanks to the increasingly versatile and robust availability of lossless supercurrent. In particular high supercurrent density can lead to more efficient and compact power transmission lines, high-field magnets, as well as high-performance nanoscale radiation detectors and superconducting spintronics. Here, we report the discovery of an unprecedentedly high superconducting critical current density (17 MA/cm2 at 0 T and 7 MA/cm2 at 8 T) in 1T'-WS2, exceeding those of all reported two-dimensional superconductors to date. 1T'-WS2 features a strongly anisotropic (both in- and out-of-plane) superconducting state that violates the Pauli paramagnetic limit signaling the presence of unconventional superconductivity. Spectroscopic imaging of the vortices further substantiates the anisotropic nature of the superconducting state. More intriguingly, the normal state of 1T'-WS2 carries topological properties. The band structure obtained via angle-resolved photoemission spectroscopy and first-principles calculations points to a Z2 topological invariant. The concomitance of topology and superconductivity in 1T'-WS2 establishes it as a topological superconductor candidate, which is promising for the development of quantum computing technology.
@article{arxiv.2301.11425,
title = {Anomalously high supercurrent density in a two-dimensional topological material},
author = {Qi Zhang and Md Shafayat Hossain and Brian Casas and Wenkai Zheng and Zi-Jia Cheng and Zhuangchai Lai and Yi-Hsin Tu and Guoqing Chang and Yao Yao and Siyuan Li and Yu-Xiao Jiang and Sougata Mardanya and Tay-Rong Chang and Jing-Yang You and Yuan-Ping Feng and Guangming Cheng and Jia-Xin Yin and Nana Shumiya and Tyler A. Cochran and Xian P. Yang and Maksim Litskevich and Nan Yao and Kenji Watanabe and Takashi Taniguchi and Hua Zhang and Luis Balicas and M. Zahid Hasan},
journal= {arXiv preprint arXiv:2301.11425},
year = {2025}
}