Charge order landscape and competition with superconductivity in kagome metals

TL;DR

This study uses high-resolution spectroscopy to elucidate the three-dimensional charge order in kagome metals AV3Sb5 and explores its interaction with superconductivity, revealing composition-dependent structural variations and their impact on superconducting behavior.

Contribution

It provides the first microscopic structural characterization of 3D charge order in AV3Sb5 and links these structures to superconductivity and doping effects.

Findings

3D-CO induces unusual splitting of kagome bands.

Charge order structure varies with composition and doping.

Differences in charge order correlate with superconducting properties.

Abstract

In kagome metals AV3Sb5 (A = K, Rb, Cs), three-dimensional charge order (3D-CO) is the primary instability that sets the stage for other collective orders to emerge, including unidirectional stripe order, orbital flux order, electronic nematicity, and superconductivity. Here, we use high-resolution angle-resolved photoemission spectroscopy to determine the microscopic structure of three-dimensional charge order (3D-CO) in AV3Sb5 and its interplay with superconductivity. Our approach is based on identifying an unusual splitting of kagome bands induced by 3D-CO, which provides a sensitive way to refine the spatial charge patterns in neighboring kagome planes. We found a marked dependence of the 3D-CO structure on composition and doping. The observed difference between CsV3Sb5 and the other compounds potentially underpins the double-dome superconductivity in CsV3(Sb,Sn)5 and the suppression of Tc in KV3Sb5 and RbV3Sb5. Our results provide fresh insights into the rich phase diagram of AV3Sb5.