High-Frequency Vortex Critical Dynamics of Superconducting Amorphous Mo₃Si Films

The effects of static disorder on the vortex dynamics of type-II superconductors are investigated by comparing the high-frequency vortex response of superconducting amorphous Mo3Si (a- Mo3Si ) films with that of the high-temperature superconductors. We find that for a- Mo3Si films in the three-dimensional limit, the microwave vortex response near the second-order vortex-solid to vortex-liquid glass transitions is consistent with vortex critical relaxation, in contrast to the diffusion vortex dynamics in high-temperature superconductors at the same frequencies. The observation of microwave vortex critical dynamics in a- Mo3Si is attributed to the extremely disordered nature of the amorphous superconductors, which results in a much shorter-range vortex correlation and therefore a faster critical relaxation.