p-wave superconductivity in cubic metals

Abstract

Group theory is used to classify p-wave superconducting states in a cubic crystal with spin-orbit coupling. All possible stable states are obtained based on the most general form of the Ginzburg-Landau free energy. Within the weak-coupling theory all stable states have real order parameters. These real states are even under time-reversal symmetry. However, in general, states with complex order parameters are also possible. In these complex states time-reversal symmetry is broken. This broken symmetry may show up through the existence of a Josephson current between a complex p-wave state and a usual s-wave superconductor. The form of the pairing in a magnetic field is also discussed.