Superconductivity in the $\mathbb{Z}_2$ kagome metal KV$_3$Sb$_5$

TL;DR

This paper reports the discovery of bulk superconductivity in the two-dimensional kagome metal KV$_3$Sb$_5$, revealing its potential as a platform for exploring topological states and electronic order in layered materials.

Contribution

It provides the first observation of superconductivity in KV$_3$Sb$_5$ and links it to the topological properties of the normal state, expanding understanding of the AV$_3$Sb$_5$ family.

Findings

Superconductivity observed below 0.93K in KV$_3$Sb$_5$

Normal state characterized as a $ ext{Z}_2$ topological metal

Superconductivity likely common in the AV$_3$Sb$_5$ family

Abstract

Here we report the observation of bulk superconductivity in single crystals of the two-dimensional kagome metal KV$_3$Sb$_5$. Magnetic susceptibility, resistivity, and heat capacity measurements reveal superconductivity below $T_c = 0.93$K, and density functional theory (DFT) calculations further characterize the normal state as a $\mathbb{Z}_2$ topological metal. Our results demonstrate that the recent observation of superconductivity within the related kagome metal CsV$_3$Sb$_5$ is likely a common feature across the AV$_3$Sb$_5$ (A: K, Rb, Cs) family of compounds and establish them as a rich arena for studying the interplay between bulk superconductivity, topological surface states, and likely electronic density wave order in an exfoliable kagome lattice.