Charge density wave orders and enhanced superconductivity under pressure in the kagome metal CsV3Sb5

TL;DR

This study investigates how charge density wave orders and superconductivity evolve under pressure in CsV3Sb5, revealing competing interactions and enhanced superconductivity up to 8.2 K, highlighting its potential for exploring topological kagome metals.

Contribution

It provides the first detailed observation of two distinct CDW orders and their interplay with superconductivity under pressure in CsV3Sb5, a topological kagome metal.

Findings

Two CDW orders correspond to 4a*1a and 2a*2a superlattices.

Superconducting transition temperature reaches 8.2 K at 1 GPa.

CDW states decline as pressure increases, indicating competition with superconductivity.

Abstract

Superconductivity in topological kagome metals has recently received great research interests. Here, charge density wave (CDW) orders and the evolution of superconductivity under various pressures in CsV3Sb5 single crystal with V kagome lattice are investigated. By using high-resolution scanning tunnelling microscopy /spectroscopy (STM/STS), two CDW orders in CsV3Sb5 are observed which correspond to 4a*1a and 2a*2a superlattices. By applying pressure, the superconducting transition temperature Tc is significantly enhanced and reaches a maximum value of 8.2 K at around 1 GPa. Accordingly, CDW state is gradually declined as increasing the pressure, which indicates the competing interplay between CDW and superconducting state in this material. The broad superconducting transitions around 0.4 - 0.8 GPa can be related to the strong competition relation among two CDW states and superconductivity. These results demonstrate that CsV3Sb5 is a new platform for exploring the interplay between superconductivity and CDW in topological kagome metals.