Magnetically mediated superconductivity in quasi-two and three dimensions - art. no. 054529

We compare predictions of the mean-field theory of superconductivity for ne arly antiferromagnetic and nearly ferromagnetic metals in two and three dim ensions. The calculations are based on a parametrization of the effective i nteraction arising from the exchange of magnetic fluctuations. The results show that for comparable parameters, magnetic pairing is more robust in qua si-two-dimensions than in three dimensions, for either p-wave (spin triplet ) pairing in nearly ferromagnetic metals or cl-wave (spin singlet) pairing in nearly antiferromagnetic metals. Moreover we find higher mean-field tran sition temperatures for d-wave pairing than for p-wave pairing (for compara ble parameters), regardless of dimensionality. We present intuitive argumen ts for why quasi-two-dimensional d-wave pairing is a particularly favorable case.