Spin-orbital coupling in a triplet superconductor-ferromagnet junction

Phys Rev Lett. 2013 Aug 30;111(9):097003. doi: 10.1103/PhysRevLett.111.097003. Epub 2013 Aug 27.

Abstract

We study the interplay of spin and orbital degrees of freedom in a triplet superconductor-ferromagnet junction. Using a self-consistent spatially dependent mean-field theory, we show that increasing the angle between the ferromagnetic moment and the triplet vector order parameter enhances or suppresses the p-wave gap close to the interface, according to whether the gap antinodes are parallel or perpendicular to the boundary, respectively. The associated change in condensation energy establishes an orbitally dependent preferred orientation for the magnetization. When both gap components are present, as in a chiral superconductor, first-order transitions between different moment orientations are observed as a function of the exchange field strength.