condensed matter physics

Strain-Tuned Nodal Superconductivity in the Charge-Ordered Kagome Metal CsVSb

arXiv:2607.11115

summary

The authors use Sb NQR to study how uniaxial tensile strain affects superconductivity in the kagome metal CsVSb, finding an enhanced and a strain‑induced double transition between nodal and nodeless gap states.

Abstract

The nature of the superconducting pairing symmetry in the kagome metal CsVSb and its relationship with the charge density wave (CDW) order are central unresolved issues. Here, we investigate the evolution of superconductivity in CsVSb under in-situ uniaxial pressure using Sb nuclear quadrupole resonance (NQR). We find that tensile strain significantly enhances the superconducting transition temperature, , while the CDW remains unchanged, demonstrating that superconductivity can be tuned independently of the bulk charge order. At a tensile strain of = +0.90%, the nuclear spin-lattice relaxation rate reveals a remarkable double transition: an upper transition at = 3.6 K to a nodal gap state, and a lower one at = 3.0 K characterized by a nodeless gap. These results evidence degenerate superconducting states with different gap symmetry in the kagome metal at ambient pressure which split under strain. Our work demonstrates a high tunability of superconductivity by uniaxial pressure.

8 pages, 8 figures, to appear in Phys. Rev. Lett

Topics & keywords

#kagome metal#superconductivity#uniaxial strain#charge density wave#nodal gapCsV3Sb5nuclear quadrupole resonancespin-lattice relaxationtensile straindouble transitionnodal superconductivity