Bulk evidence of anisotropic s-wave pairing with no sign change in the kagome superconductor CsV3Sb5

Abstract

In the kagome superconductor CsV3Sb5 the symmetry of the superconducting gap is still in question, both at ambient pressure and under high pressure. Here, via controlled introduction of impurities, the authors report evidence for a non-chiral full superconducting gap with no sign change.