Back to Search
Start Over
Bulk evidence of anisotropic $s$-wave pairing with no sign change in the kagome superconductor CsV$_3$Sb$_5$
- Source :
- Nat. Commun. 14, 667 (2023)
- Publication Year :
- 2022
-
Abstract
- The recently discovered kagome superconductors $A$V$_3$Sb$_5$ ($A$ = K, Rb, Cs) possess a unique band structure with van Hove singularities and Dirac dispersions, in which unusual charge-density-wave (CDW) orders with time-reversal and rotational symmetry breaking have been reported. One of the most crucial unresolved issues is identifying the symmetry of the superconductivity that develops inside the CDW phase. Theory predicts a variety of unconventional superconducting symmetries, including exotic states with chiral and topological properties accompanied by a sign-changing superconducting gap. Experimentally, however, the phase information on the superconducting gap in $A$V$_3$Sb$_5$ is still lacking. Here we report the electron irradiation effects in CsV$_3$Sb$_5$ using introduced impurities as a phase-sensitive probe of superconductivity. Our magnetic penetration depth measurements reveal that with increasing impurities, a highly anisotropic fully-gapped state changes gradually to an isotropic full-gap state without passing through a nodal state. Furthermore, transport measurements under high pressure show that the double superconducting dome in the pressure-temperature phase diagram survives against sufficient impurities. These results are strong bulk evidence that CsV$_3$Sb$_5$ is a non-chiral, anisotropic $s$-wave superconductor with no sign change both at ambient and high pressure, which provides a clue to understanding the relationship between CDW and superconductivity in kagome superconductors.<br />Comment: 22 pages, 4 figures
Details
- Database :
- arXiv
- Journal :
- Nat. Commun. 14, 667 (2023)
- Publication Type :
- Report
- Accession number :
- edsarx.2206.02580
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1038/s41467-023-36273-x