Two-gap s± -wave superconductivity at an oxide interface

After half a century of debate, superconductivity in doped SrTiO3 has come to the fore again with the discovery of interfacial superconductivity in the LaAlO3 /SrTiO3 heterostructures. While these interfaces share the interesting properties of bulk SrTiO3, quantum confinement generates a complex ban...

Descripción completa

Detalles Bibliográficos
Autores: Singh, Gyanendra, Venditti, G., Saiz, Guilhem, Herranz, Gervasi, Sánchez Barrera, Florencio, Jouan, Alexis, Feuillet-Palma, Chéryl, Lesueur, Jerome, Grilli, Marco, Caprara, Sergio, Bergeal, ‪Nicolas
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2022
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/269656
Acceso en línea:http://hdl.handle.net/10261/269656
https://api.elsevier.com/content/abstract/scopus_id/85126045148
Access Level:acceso abierto
Palabra clave:Impurities in superconductors
Multiband superconductivity
Superconducting gap
Superconducting phase transition
Descripción
Sumario:After half a century of debate, superconductivity in doped SrTiO3 has come to the fore again with the discovery of interfacial superconductivity in the LaAlO3 /SrTiO3 heterostructures. While these interfaces share the interesting properties of bulk SrTiO3, quantum confinement generates a complex band structure involving bands with different orbital symmetries whose occupancy is tunable by electrostating doping. Multigap superconductivity has been predicted to emerge in LaAlO3 /SrTiO3 at large doping, with a Bose-Einstein condensation character at the Lifshtiz transition. In this article, we report on the measurement of the upper critical magnetic field Hc2 of superconducting (110)-oriented LaAlO3 /SrTiO3 heterostructures and evidence a two-gap superconducting regime at high doping. Our results are quantitatively explained by a theoretical model based on the formation of an unconventional s±-wave superconducting state with a repulsive coupling between the two condensates.