Nonequilibrium effects in the thermal switching of underdamped Josephson junctions

We study the thermal escape problem in the low damping limit. We find that finiteness of the barrier is crucial for explaining the thermal activation results. In this regime, low barrier nonequilibrium corrections to the usual theories become necessary. We propose a simple theoretical extension accounting for these nonequilibrium processes which agrees numerical results. We apply our theory to the understanding of switching current curves in underdamped Josephson junctions.