Dynamics of electronic transport in a semiconductor superlattice with a shunting side layer

TL;DR

This paper models electronic transport in semiconductor superlattices with shunting layers, revealing how size and shunt quality influence field stability and dynamic behaviors, with implications for THz device design.

Contribution

It introduces a detailed model analyzing the effects of shunt properties and size on field stability and dynamics in superlattices, highlighting conditions for uniform fields and oscillations.

Findings

Small superlattices with high-quality shunts have stable uniform fields.

Larger superlattices tend to develop static or dynamic field domains.

Lower quality shunts induce complex oscillations and bifurcations.

Abstract

We study a model describing electronic transport in a weakly-coupled semiconductor superlattice with a shunting side layer. Key parameters include the lateral size of the superlattice, the connectivity between the quantum wells of the superlattice and the shunt layer, and the conduction properties of the shunt layer. For a superlattice with small lateral extent and high quality shunt, static electric field domains are suppressed and a spatially-uniform field configuration is predicted to be stable, a result that may be useful for proposed devices such as a superlattice-based TeraHertz (THz) oscillators. As the lateral size of the superlattice increases, the uniform field configuration loses its stability to either static or dynamic field domains, regardless of shunt properties. A lower quality shunt generally leads to regular and chaotic current oscillations and complex spatio-temporal dynamics in the field profile. Bifurcations separating static and dynamic behaviors are characterized and found to be dependent on the shunt properties.