Transport statistics in bistable systems, a stochastic path integral approach

We consider the non-equilibrium noise properties of bistable systems. The stochastic path integral formalism is derived and used to investigate the dynamics and distribution of transmitted charge. Microscopic fluctuations induce transitions between the two stable states, with rates found from an instanton calculation. On a long time scale, the system exhibits a random telegraph signal between the currents produced by the two stable states. We predict a universal ellipse law for the log-distribution of transmitted charge in the bistable current range, which applies to any type of bistable system, regardless of its origin.