Group theoretical analysis of the lattice distorsion in anisotropic Superconductivity

Abstract

This report describes the group theoretical determination of the possible type of the uniform lattice distortion associated with the superconducting transition when the order parameter belongs to a degenerate representation of the symmetry group of the system. The method uses the symmetrical property of the Ginzburg-Landau functional with the lattice distortion. Systems with hexagonal (D6) and tetragonal (D4) symmetry are studied in the presence of the spin-orbit coupling. It is shown that all states (except 3 states) with the order parameter of the degenerate representation in regard to D6 or D4 are unstable to the lattice distortion which breaks the symmetrical configuration.