Hot Brownian Carriers in the Langevin Picture: Application to a simple model for the Gunn Effect in GaAs

TL;DR

This paper models hot Brownian carriers in GaAs using Langevin dynamics, revealing a negative differential conductivity regime similar to the Gunn effect, and compares theoretical results with experiments.

Contribution

It introduces a Langevin-based model for hot carriers in GaAs that captures the Gunn effect and matches experimental observations.

Findings

Identifies a negative differential conductivity regime in the model.

Provides a theoretical explanation for the Gunn effect in GaAs.

Shows agreement between the model and experimental data.

Abstract

We consider a charged Brownian gas under the influence of external, static and uniform electric and magnetic fields, immersed in a uniform bath temperature. We obtain the solution for the associated Langevin equation, and thereafter the evolution of the nonequilibrium temperature towards a nonequilibrium (hot) steady state. We apply our results to a simple yet relevant Brownian model for carrier transport in GaAs. We obtain a negative differential conductivity regime (Gunn effect) and discuss and compare our results with experimental results.