Edge states and determination of pairing symmetry in superconducting Sr₂RuO₄

Abstract

We calculate the energy dispersion of the surface Andreev states and their contribution to tunneling conductance for the order parameters with horizontal and vertical lines of nodes proposed for superconducting Sr₂RuO₄. For vertical lines, we find double peaks in tunneling spectra reflecting the van Hove singularities in the density of surface states originating from the turning points in their energy dispersion. For horizontal lines, we find a single cusplike peak at zero bias, which agrees very well with the experimental data on tunneling in Sr₂RuO₄.