Photoemission Insights to Electronic Orders in Kagome Superconductor AV3Sb5

TL;DR

This review summarizes recent ARPES studies on AV3Sb5 kagome superconductors, revealing insights into their electronic structure, charge density waves, and superconducting properties, advancing understanding of their exotic electronic phenomena.

Contribution

The paper compiles and analyzes recent ARPES findings, providing new insights into the electronic orders and pairing mechanisms in AV3Sb5 kagome superconductors.

Findings

Identification of multiple van Hove singularities near the Fermi level

Observation of CDW-induced symmetry breaking features

Detection of nodeless superconducting gaps and moderate electron-phonon coupling

Abstract

Kagome superconductors AV3Sb5 (A = K, Rb, and Cs) have attracted considerable attention due to their intriguing combination of unique electron correlations and nontrivial band topology. The interplay of these fundamental aspects gives rise to a diverse array of exotic electronic phenomena, including superconductivity and charge density wave (CDW) states. In this review, we present recent advancements in the study of the electronic band structure of AV3Sb5 using angle-resolved photoemission spectroscopy (ARPES), including the identification of the multiple van Hove singularities near the Fermi level and their close relationship with the CDW transition, spectroscopic features related to CDW-induced symmetry breakings, as well as direct observations of nodeless superconducting gaps and moderate electron-phonon couplings through ultrahigh-resolution ARPES, providing critical insights into the origins of CDW order and electron pairing symmetry. By synthesizing these key ARPES findings, this review aims to deepen our understanding of kagome-related physics.