Two-gap s± -wave superconductivity at an oxide interface
Journal article, 2022

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.

Author

Gyanendra Singh

Institute of Material Science of Barcelona (ICMAB)

Université Paris PSL

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

G. Venditti

Sapienza University of Rome

Istituto Dei Sistemi Complessi, Rome

G. Saiz

Université Paris PSL

G. Herranz

Institute of Material Science of Barcelona (ICMAB)

F. Sánchez

Institute of Material Science of Barcelona (ICMAB)

A. Jouan

Université Paris PSL

C. Feuillet-Palma

Université Paris PSL

J. Lesueur

Université Paris PSL

M. Grilli

Sapienza University of Rome

Istituto Dei Sistemi Complessi, Rome

S. Caprara

Istituto Dei Sistemi Complessi, Rome

Sapienza University of Rome

N. Bergeal

Université Paris PSL

Physical Review B

24699950 (ISSN) 24699969 (eISSN)

Vol. 105 6 064512

Subject Categories

Other Physics Topics

Theoretical Chemistry

Condensed Matter Physics

DOI

10.1103/PhysRevB.105.064512

More information

Latest update

3/21/2022