Effects of asymmetric geometry and surface defects on vortical configurations in mesoscopic superconducting loops

Abstract

In the framework of the microscopic Bogoliubov–de Gennes theory, we investigate the vortical patterns of dominant chiral p-wave orders in mesoscopic asymmetric superconducting loops. For the case of rectangular samples with a small ratio of length to height Ny/Nx, a coreless skyrmionic-like mode containing separated one-component vortices can be obtained. With further increasing Ny/Nx, such a spatial structure is broken due to the aspect-radio effect, and singular vortices with point-like cores tend to appear. In addition, when an indentation defect is introduced at the outer boundary of a mesoscopic square or rectangular loop, the order modulations are strongly affected by the locations of the surface defect, and several peculiar vortical configurations inside the sample can be presented.