Vortex dynamics in amorphous MoSi superconducting thin films

Abstract

Vortex dynamics in superconductors have received a great deal of attention from both fundamental and applied researchers over the past few decades. Because of their critical role in the energy relaxation process of type-II superconductors, vortex dynamics have been deemed a key factor for the emerging superconducting devices, but the effect of irradiation on vortex dynamics remains unclear. With the support of electrical transport measurements under external magnetic fields and irradiation, the photon effect on vortex dynamics in amorphous MoSi (a-MoSi) superconducting thin films is investigated in this work. The magnetic-field-dependent critical vortex velocity v* derived from the Larkin–Ovchinnikov (LO) model is not significantly affected by irradiation. However, vortex depinning is found to be enhanced by photon-induced reduction in the potential barrier, which mitigates the adverse effect of film inhomogeneity on superconductivity in the a-MoSi thin films. A thorough understanding of the vortex dynamics in a-MoSi thin films under the effect of external stimuli is of paramount importance for both further fundamental research in this area and the optimization of future superconducting devices.