History-dependent dissipative vortex dynamics in superconducting arrays

Abstract: We perform current(I)-voltage(V) measurements on low resistance superconductor-normal-superconductor arrays in finite magnetic fields, focusing on the dilute vortex population regime. We observe significant deviations from predicted behavior, notably the absence of a differential resistance peak near the vortex de-pinning current, and a broad linear I-V region with an extrapolated I intercept equal to the de-pinning current. Comparing these results to an overdamped molecular vortex model, we find that this behavior can be explained by the presence of a history dependent dissipative force. This approach has not been considered previously, yet is crucial for obtaining a correct description of the vortex dynamics in superconducting arrays.