Spontaneous Magnetization and Nonmagnetic Defect Effects in Mesoscopic <i>s</i>+i<i>s</i> Superconductors

Based on the two-band time-dependent Ginzburg–Landau theory, we have studied the electromagnetic properties of mesoscopic s + i s superconductors with different defect configurations. We have performed our numerical simulations with the finite element method and give direct evidence of spontaneous magnetization induced by the isotropic defect in this superconducting system. Additionally, regarding various impurity numbers, we have investigated the influences of the Ginzburg–Landau parameter ᴋ and defect size on the patterns of spontaneous magnetization distribution. Our theoretical results thus indicate that the defect characteristics will significantly affect the magnetic properties in multiband superconductors with time-reversal symmetry breaking.