Nonequilibrium dynamics in type-II superconductors with inhomogeneous vortex pinning

We study numerically the dynamics relating to negative vortex motion in inhomogeneous pinning systems. We show that this dynamical phenomenon results from the internal field e ect produced by the growing local barriers with decreasing temperature. We find that the negative motion is characterized by a peak of negative voltage or resistance in resistance-temperature transport measurements. We also demonstrate that the time window to observe the negative motion is determined by the magnitude of driving force in addition to the temperature scanning rate.