Noise-induced dynamics in far-from-equilibrium electronic transport systems

Bistable systems occur throughout the natural sciences and when such systems are subjected to noise, one observes probabilistic transitions between co-existing metastable states. Such behavior is found in chemical reaction kinetics, driven nonlinear mechanical systems, nonlinear electronic transport systems, climate dynamical models, and pulse propagation dynamics in neurons, to name but a few. In the case of electronic transport systems, experimental studies focus on probabilistic switching transitions between distinct states of electrical current flow in tunneling structures such as semiconductor superlattices and tunnel diodes. In particular, tunnel diode circuits provide an excellent experimental platform for the precision measurement of switching time statistics over a wide dynamic range. Furthermore, the measurement of mean switching times versus system parameters such as applied voltage near bifurcation points allows the determination of scaling behavior with remarkable precision. In related work, we have experimentally and theoretically studied linear electrical networks that are driven by non-thermal noise sources with a focus on the development of novel methods to characterize violations of detailed balance. Three methods of particular interest for experiments are: 1) construction of probability current from data, 2) stochastic area measurement, and 3) construction of statistical fluctuation loops. In this talk, we highlight the advantages and limitations of each of these approaches.