Physical Review Research (Nov 2022)
Vortex supercurrent inversion by frequency-symmetry conversion of Cooper pairs
Abstract
We theoretically demonstrate that the vortex supercurrent can be reversed by the frequency-symmetry conversion among Cooper pairs by surface Andreev bound states. The surface of a three-dimensional superconductor pierced by a flux quantum is considered. We compare the vortex supercurrents near the surface of the spin-singlet s-wave and spin-triplet p_{z}-wave superconductors using quasiclassical Eilenberger theory, where the surface is perpendicular to the z direction. We demonstrate that the vortex supercurrent near the surface of a p_{z}-wave superconductor is reversed compared to those far from the surface, whereas that of an s-wave superconductor is not. The splitting of the zero-energy states caused by the interference of the surface Andreev bound states and Caroli-de Gennes-Matricon modes is demonstrated.