Superconductivity from Repulsion: Ginzburg–Landau Phenomenology of Cuprates

Abstract

We develop Ginzburg-Landau approach to the problem of superconducting pairing with large momentum under screened Coulomb repulsion (η K -pairing). Two-component order parameter arising in this scheme can be associated with charge and orbital current degrees of freedom of the relative motion of η K -pair corresponding to superconducting and orbital antiferromagnetic ordered states, respectively. All basic features of the phase diagram of cuprate superconductors result directly from the η K -pairing concept.