Stochastic thermal feedback in switching measurements of a superconducting nanobridge caused by overheated electrons and phonons

Abstract

We study correlated switchings of a superconducting nanobridge probed with a train of current pulses. For pulses with a low repetition rate each pulse transits the superconducting bridge to the normal state with probability P independent of the outcomes in the preceding pulses. We show that with the reduction of the time interval between pulses long-range correlation between pulses occurs: stochastic switching in a single pulse raises the temperature of the bridge and affects the outcome of the probing for the next pulses. As a result, an artificial intricate stochastic process with an adjustable strength of correlation is produced. We identify the regime where apparent switching probability exhibits the thermal hysteresis with discontinuity at a critical current amplitude of the probing pulse. This engineered stochastic process can be viewed as an artificial phase transition and provides an interesting framework for studying correlated systems. The process resembles the familiar transition from the superconducting to normal state in the current-bias nanowire, proceeding through a phase slip avalanche. Due to its extreme sensitivity to the control parameter, i.e., electric current, temperature, or magnetic field, it offers the opportunity for ultrasensitive detection.

Source-reported materials — not catalogue approval

Similar papers