Accelerated, decelerated, and oscillating fronts in a globally coupled bistable semiconductor system

Abstract

We study front propagation in a globally coupled bistable semiconductor system. The analysis is based on an activator-inhibitor model derived for a gate-driven $\mathrm{pnpn}$ structure that is globally coupled via a gate-cathode circuit, but the model is applicable for more general cases of a spatially extended system with Z-shaped bistability. We demonstrate that a global constraint allows for efficient control over the front propagation. In the voltage-driven regime the front propagates with a constant speed whose value and direction are controlled by the gate potential. Under general gate circuit conditions the front dynamics experiences either a positive or a negative feedback which acts with adjustable delay. This allows for tuning between accelerated, decelerated, and oscillating fronts.