Giant vortex structures in mesoscopic spherical type-II superconducting samples

Abstract

Giant vortex states which can occur in type-II mesoscopic spherical superconducting samples embedded in different materials have been studied within the framework of the nonlinear Ginzburg–Landau theory. The proposed method, which is based on presentation of the superconducting order parameter in a form of the spherical functions expansion gives the possibility to take into account different types of boundary condition.The upper critical field of a superconducting spherical inclusion was calculated for different types of the three-dimensional boundary condition.