Distinct switching of chiral transport in the kagome metals KV$_3$Sb$_5$ and CsV$_3$Sb$_5$

TL;DR

This study compares magneto-chiral transport in KV3Sb5 and CsV3Sb5, revealing that only CsV3Sb5 exhibits field-switchable eMChA, indicating the importance of correlated states beyond band structure in these kagome metals.

Contribution

It provides the first comparative analysis of magneto-chiral transport in KV3Sb5 and CsV3Sb5, highlighting the role of correlated states in eMChA behavior.

Findings

CsV3Sb5 shows non-saturating, field-switchable eMChA up to 35 T.

KV3Sb5 exhibits negligible eMChA, with no field switchability.

Differences suggest correlated states, not just band structure, govern eMChA in these materials.

Abstract

The kagome metals AV$_3$Sb$_5$ (A=K,Rb,Cs) present an ideal sandbox to study the interrelation between multiple coexisting correlated phases such as charge order and superconductivity. So far, no consensus on the microscopic nature of these states has been reached as the proposals struggle to explain all their exotic physical properties. Among these, field-switchable electric magneto-chiral anisotropy (eMChA) in CsV$_3$Sb$_5$ provides intriguing evidence for a rewindable electronic chirality, yet the other family members have not been likewise investigated. Here, we present a comparative study of magneto-chiral transport between CsV$_3$Sb$_5$ and KV$_3$Sb$_5$. Despite their similar electronic structure, KV$_3$Sb$_5$ displays negligible eMChA, if any, and with no field switchability. This is in stark contrast to the non-saturating eMChA in CsV$_3$Sb$_5$ even in high fields up to 35 T. In light of their similar band structures, the stark difference in eMChA suggests its origin in the correlated states. Clearly, the V kagome nets alone are not sufficient to describe the physics and the interactions with their environment are crucial in determining the nature of their low-temperature state.