High temperature superconductivity with repulsive pairing interactions

Highlight•Non-separable interaction kernels with a separable repulsive part produce anomalous high temperature superconductivity with a first order phase transition and negative specific heat near TC.

A pairing Hamiltonian H(Γ)H(Γ) with an interaction kernel Γ   characterized by [-Γ0,-α0][-Γ0,-α0], where Γ0Γ0 denotes the separable part and α0α0 the degree of non-separability, produces high temperature superconductivity for both attractive Γ0>0Γ0>0 and repulsive Γ0<0Γ0<0 when α0>0α0>0. For Γ0>0Γ0>0, typical HTS properties, e.g. cuprate, are produced. Repulsive Γ0<0Γ0<0 produces a distinct difference in the kinetic energy dependence of the SC gap, significantly altering thermodynamic properties.