Intrinsic nature of chiral charge order in the kagome superconductor RbV3Sb5

TL;DR

This study reveals the intrinsic chiral charge order in the kagome superconductor RbV3Sb5, showing its magnetic field tunability and interaction with nematic surface superlattices, advancing understanding of charge order phenomena in kagome superconductors.

Contribution

The paper provides the first direct STM evidence of intrinsic chiral charge order in RbV3Sb5 and explores its interaction with nematic surface superlattices, highlighting new aspects of charge order in kagome superconductors.

Findings

Observation of 2x2 chiral charge order in RbV3Sb5

Chiral charge order exhibits magnetic field tunability

Interaction between charge order and nematic superlattices

Abstract

Superconductors with kagome lattices have been identified for over 40 years, with a superconducting transition temperature TC up to 7K. Recently, certain kagome superconductors have been found to exhibit an exotic charge order, which intertwines with superconductivity and persists to a temperature being one order of magnitude higher than TC. In this work, we use scanning tunneling microscopy (STM) to study the charge order in kagome superconductor RbV3Sb5. We observe both a 2x2 chiral charge order and nematic surface superlattices (predominantly 1x4). We find that the 2x2 charge order exhibits intrinsic chirality with magnetic field tunability. Defects can scatter electrons to introduce standing waves, which couple with the charge order to cause extrinsic effects. While the chiral charge order resembles that discovered in KV3Sb5, it further interacts with the nematic surface superlattices that are absent in KV3Sb5 but exist in CsV3Sb5.