Chiral flux phase in the Kagome superconductor AV$_3$Sb$_5$

TL;DR

This paper proposes that the topological charge density wave phase in the Kagome superconductor AV$_3$Sb$_5$ is a chiral flux phase that breaks time-reversal symmetry and exhibits an anomalous Hall effect, supported by experimental evidence.

Contribution

It identifies the chiral flux phase as the lowest energy state with observed charge order, linking topology, symmetry, and experimental findings in AV$_3$Sb$_5$.

Findings

Chiral flux phase breaks time-reversal symmetry.

State exhibits anomalous Hall effect.

Pattern of density calculated and supported by experiments.

Abstract

We argue that the topological charge density wave phase in the quasi-2D Kagome superconductor AV$_3$Sb$_5$ is a chiral flux phase. Considering the symmetry of the Kagome lattice, we show that the chiral flux phase has the lowest energy among those states which exhibit $2\times2$ charge orders observed experimentally. This state breaks the time-reversal symmetry and displays anomalous Hall effect. The explicit pattern of the density of this state in real space is calculated. These results are supported by recent experiments and suggest that these materials are a new platform to investigate the interplay between topology, superconductivity and electron-electron correlations.