Kagome superconductors AV$_3$Sb$_5$ (A=K, Rb, Cs)

TL;DR

This review discusses the recent experimental and theoretical advances in kagome superconductors AV$_3$Sb$_5$, highlighting their unique electronic properties, charge density wave phenomena, potential unconventional pairing mechanisms, and the interplay between superconductivity and symmetry breaking.

Contribution

It provides a comprehensive overview of the current understanding of AV$_3$Sb$_5$ kagome superconductors, integrating experimental findings and theoretical models to guide future research.

Findings

Evidence of charge density wave order in AV$_3$Sb$_5$

Signs of time-reversal symmetry breaking

Potential unconventional superconducting pairing mechanisms

Abstract

The quasi two-dimensional (quasi-2D) kagome materials AV$_3$Sb$_5$ (A=K, Rb, Cs) were found to be a prime example of kagome superconductors, a new quantum platform to investigate the interplay between electron correlation effects, topology and geometric frustration. In this review, we report recent progress on the experimental and theoretical studies of AV$_3$Sb$_5$ and provide a broad picture of this fast-developing field in order to stimulate an expanded search for unconventional kagome superconductors. We review the electronic properties of AV$_3$Sb$_5$, the experimental measurements of the charge density wave state, evidence of time-reversal symmetry breaking, and other potential hidden symmetry breaking in these materials. A variety of theoretical proposals and models that address the nature of the time-reversal symmetry breaking are discussed. Finally, we review the superconducting properties of AV$_3$Sb$_5$, especially the potential pairing symmetries and the interplay between superconductivity and the charge density wave state.