Journal of Superconductivity and Novel Magnetism (2025) 38:158
Authors: Pablo García Talavera, Jose Antonio Moreno, Edwin Herrera, Alexander I. Buzdin, Sergey L. Bud’ko, Paul C. Canfield, Isabel Guillamón & Hermann Suderow
Abstract: PtPb is a type II superconductor with a bulk critical temperature K and an upper critical field of T. PtPb is related to non-superconducting PtSn, which presents nodal arc states at the surface. Here, we measure the superconducting density of states of PtPb using millikelvin Scanning Tunneling microscopy (STM). We observe a fully opened superconducting gap of meV similar to expectations from Bardeen, Cooper and Schrieffer (BCS) theory ( meV). Measurements under magnetic fields applied perpendicular to the surface show a spatially inhomogeneous gap structure, presenting superconducting signatures at fields as high as 1.5 T, significantly above T. On some locations, we find that the superconducting density of states does not vanish above . We can find signatures of a superconducting gap up to 5 K. We discuss possible reasons for the observation of superconducting properties above and , emphasizing the role played by structural defects.
