Onset of superconductivity and hysteresis in magnetic field for a long cylinder as obtained from a self-consistent solutions of the Ginzburg--Landau equations

Abstract

Based on the self-consistent solution of a nonlinear system of one-dimensional GL-equations, the onset and destruction of superconductivity, the phase transitions and hysteresis phenomena are discussed for a cylinder (radius R) in an axial magnetic field (H) for arbitrary R,kappa,H,m (kappa$ is the GL-parameter, m is the total vorticity of the system). The edge-suppressed solutions (which are connected with the jumps of magnetization in the states with fixed vorticity m), the depressed solutions (responsible for the hysteresis in type-II superconductors), and the precursor solutions (which describe the onset of superconductivity in type-I superconductors) are also studied. The limits of applicability of the so-called linear equation approximation are discussed.