Superconducting Density of States of PtPb4

PtPb4 is a type II superconductor with a bulk critical temperature Tc ≈ 3 K and an upper critical field of Hc2 = 0.36T. PtPb4 is related to non-superconducting PtSn4, which presents nodal arc states at the surface. Here, we measure the superconducting density of states of PtPb4 using millikelvin Sca...

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Detalles Bibliográficos
Autores: García Talavera, Pablo, Moreno Flores, José Antonio, Herrera Vasco, Edwin, Buzdin, Alexander I., Bud’ko, Sergey, Canfield, Paul C., Guillamón Gómez, Isabel, Suderow Rodríguez, Hermann Jesús
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Universidad Autónoma de Madrid
Repositorio:Biblos-e Archivo. Repositorio Institucional de la UAM
Idioma:inglés
OAI Identifier:oai:repositorio.uam.es:10486/720047
Acceso en línea:http://hdl.handle.net/10486/720047
https://dx.doi.org/10.1007/s10948-025-06995-8
Access Level:acceso abierto
Palabra clave:Superconductivity
Critical temperature
Twinning planes
Binary intermetallic compounds
Scanning Tunneling Microscopy
Very low temperatures
Física
Descripción
Sumario:PtPb4 is a type II superconductor with a bulk critical temperature Tc ≈ 3 K and an upper critical field of Hc2 = 0.36T. PtPb4 is related to non-superconducting PtSn4, which presents nodal arc states at the surface. Here, we measure the superconducting density of states of PtPb4 using millikelvin Scanning Tunneling Microscopy (STM). We observe a fully opened superconducting gap of = 0.48 meV similar to expectations from Bardeen, Cooper and Schrieffer (BCS) theory (0 = 1.76kB Tc = 0.49 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 Hc2 = 0.36 T. On some locations, we find that the superconducting density of states does not vanish above Tc. We can find signatures of a superconducting gap up to 5 K. We discuss possible reasons for the observation of superconducting properties above Tc andHc2, emphasizing the role played by structural defects