Abstract
We introduce a model to explain the observed ferromagnetism and superconductivity in oxide interface structures. Because of the polar catastrophe mechanism, charge per unit cell is transferred to the interface layer. We argue that this charge localizes and orders ferromagnetically via exchange with the conduction electrons. Ordinarily, this ferromagnetism would destroy superconductivity, but, due to strong spin-orbit coupling near the interface, the magnetism and superconductivity can coexist by forming a Fulde-Ferrell-Larkin-Ovchinikov-type condensate of Cooper pairs at finite momentum, which is surprisingly robust in the presence of strong disorder.
- Received 27 July 2011
DOI:https://doi.org/10.1103/PhysRevLett.108.117003
© 2012 American Physical Society