Fyzikální ústav Akademie věd ČR

Interface-superconductivity in the presence of Rashba spin-orbit coupling and magnetic fields

Seminar Thursday, 18/10/2012 15:00

Speakers: Florian Loder (University of Augsburg)
Place: Knihovna FZÚ AV ČR, Cukrovarnická 10, Praha 6
Presented in English
Organisers: Department of Magnetics and Superconductors

Two-dimensional electron systems at oxide interfaces are influenced by a Rashba type spin-orbit coupling (SOC), which is tunable by a transverse electric field. Ferromagnetism at the interface can simultaneously induce strong local magnetic fields. This combination of SOC and magnetic fields leads to anisotropic two-sheeted Fermi surfaces, which enforces superconductivity with finite-momentum pairing. We derive a generalized pairing model realizing both, the Fulde-Ferrell-Larkin-Ovchinnikov superconductor in the limit of vanishing SOC and a mixed-parity pairing state with zero pair momentum in the absence of a magnetic field. In both limits, and also in the intermediate regime, we determine the superconducting order parameter self-consistently. We characterize the nature of this unusual pairing state and discuss it in the context of superconductivity in coexistence with ferromagnetism at LaAlO3-SrTiO3 interfaces.

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