Superconductors with spin-orbit interactions

The effect of spin-orbit (SO) interaction on the formation of the critical states in thin superconducting films in magnetic field oriented along the film is investigated. Hereby, the case of interband pairing is considered. It was found that eight branches exist in the plane of two parameters (γ1,γ2) determined by the value of magnetic field and SO interaction. Six modes leads to inhomogeneous states with different values of the impulse Q. Each state is doubly degenerate over direction of impulse Q. The parameter values at critical point are found for all eight branches in explicit form for zero temperature. The optimal two branches are estimated, corresponding to largest critical magnetic field value for given SO interaction.