Carrier Injection and Manipulation of Charge-Density Wave in Kagome Superconductor CsV3Sb5

TL;DR

This study demonstrates successful electron doping of CsV3Sb5 using Cs dosing, revealing orbital-selective effects on charge-density wave suppression and providing insights into manipulating CDW and superconductivity in kagome metals.

Contribution

It introduces an effective Cs dosing method for electron doping in CsV3Sb5 and uncovers orbital-specific effects on CDW suppression, advancing understanding of multi-orbital influences.

Findings

Electron doping increases Sb 5pz and V 3dxz/yz band fillings.

Charge-density wave can be completely suppressed by Cs dosing.

The V 3dxy/x2-y2 saddle point remains pinned at the Fermi level after doping.

Abstract

Kagome metals AV3Sb5 (A = K, Rb, and Cs) exhibit a unique superconducting ground state coexisting with charge-density wave (CDW), whereas how these characteristics are affected by carrier doping remains unexplored because of the lack of an efficient carrier-doping method. Here we report successful electron doping to CsV3Sb5 by Cs dosing, as visualized by angle-resolved photoemission spectroscopy. We found that the electron doping with Cs dosing proceeds in an orbital-selective way, as characterized by a marked increase in electron filling of the Sb 5pz and V 3dxz/yz bands as opposed to relatively insensitive nature of the V 3dxy/x2-y2 bands. By monitoring the temperature evolution of the CDW gap around the M point, we found that the CDW can be completely killed by Cs dosing while keeping the saddle point with the V 3dxy/x2-y2 character almost pinned at the Fermi level. The present result suggests a crucial role of multi-orbital effect to the occurrence of CDW, and provides an important step toward manipulating the CDW and superconductivity in AV3Sb5.