Stochastic current switching in bistable resonant tunneling systems

TL;DR

This paper analyzes the stochastic switching behavior in bistable resonant tunneling systems, providing detailed expressions for mean switching times and exploring how sample geometry influences switching initiation points.

Contribution

It derives comprehensive formulas for switching times in bistable resonant-tunneling structures, including effects of geometry and conductivity, and reveals universal behavior upon voltage renormalization.

Findings

Switching times depend exponentially on bias from the threshold.

Sample geometry influences whether switching starts inside, at the edge, or at a corner.

Results exhibit universal form after voltage renormalization.

Abstract

Current-voltage characteristics of resonant-tunneling structures often exhibit intrinsic bistabilities. In the bistable region of the I-V curve one of the two current states is metastable. The system switches from the metastable state to the stable one at a random moment in time. The mean switching time \tau depends exponentially on the bias measured from the boundary of the bistable region V_{th}. We find full expressions for \tau (including prefactors) as functions of bias, sample geometry, and in-plane conductivity. Our results take universal form upon appropriate renormalization of the threshold voltage V_{th}. We also show that in large samples the switching initiates inside, at the edge, or at a corner of the sample depending on the parameters of the system.