Chiral d-wave superconductor with nonzero center-of-mass pair momentum

Abstract

Hypothetical topologically nontrivial superconducting state of two-dimensional electron system is discussed in connection with the problem of pairing with large center-of-mass pair momentum under predominant repulsive screened Coulomb interaction. Direct numerical solution of the selfconsistency equation exhibits two nearly degenerate order parameters which can be formally referred to dx 2 −y 2 and d xy orbital symmetry. Spontaneous breaking of the time-reversal symmetry can mix these states and form fully gapped chiral d + id superconducting state.