Eliashberg study of superconductivity induced by interfacial coupling to antiferromagnets

Abstract

We perform Eliashberg calculations for magnon-mediated superconductivity in a normal metal, where the electron-magnon interaction arises from interfacial coupling to antiferromagnetic insulators. In agreement with previous studies, we find p-wave pairing for large doping when the antiferromagnetic interfaces are uncompensated and d-wave pairing close to half filling when the antiferromagnetic interfaces are compensated. However, for the p-wave phase, we find a considerable reduction in the critical temperature compared to previous weak-coupling results, as the effective frequency cutoff on the magnon propagator in this case is found to be much smaller than the cutoff on the magnon spectrum. The d-wave phase, on the other hand, relies less on long-wavelength magnons, leading to a larger effective cutoff on the magnon propagator. Combined with a large density of states close to half filling, this might allow the d-wave phase to survive up to higher critical temperatures. Based on our findings, we provide insight into how to realize interfacially induced magnon-mediated superconductivity in experiments.