Anomalously high supercurrent density in a two-dimensional topological material

TL;DR

This paper reports the discovery of an unprecedentedly high supercurrent density in 1T'-WS2, a two-dimensional material exhibiting unconventional, anisotropic superconductivity with topological properties, making it a promising candidate for quantum computing applications.

Contribution

It presents the first observation of extremely high supercurrent density in 1T'-WS2, revealing its unconventional and topological superconducting nature, which surpasses previous 2D superconductors.

Findings

Supercurrent density of 17 MA/cm2 at 0 T

Anisotropic superconducting state violating Pauli limit

Presence of topological properties in the normal state

Abstract

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.