Physical review b vol:53 issue:19 pages:12889-12895
A model of hopping conductivity is proposed that takes into account the nonlinear dependence of the mobility of the charge carriers on an externally applied field. The latter is known to be the main origin of the creation of high-field domains in n-type polar semiconductors and is responsible there for the current oscillations observed in the so-called Gunn effect. In this paper we study the effect of the non-Ohmic response to the external field via a driven diffusive lattice gas. Computer simulations carried out on our model reveal Gunn-like behavior. We present a theoretical analysis identifying the macroscopically relevant evolution equation.