Exchange interaction for the triplet superconductor URhGe

Abstract URhGe is a ferromagnetic superconductor with a low critical temperature. We use a combination of first-principles density functional calculations and modified Bardeen-Cooper-Schrieffer (BCS) theory to investigate its unconventional superconductivity. Focusing on a spin-triplet state and exchange interaction between electrons, we are able to derive the critical temperature and an average superconducting gap at 0 K that are reasonably close to the experimental value. A spin wave analysis follows that includes a dispersion relation and parameters related to the exchange interaction at low temperatures, suggesting feasible ways for experimental verification.