Abstract
A drift-diffusion model of miniband transport in strongly coupled superlattices is derived from the single-miniband Boltzmann-Poisson transport equation with a Bhatnagar-Gross-Krook collision term. We use a consistent Chapman-Enskog method to analyze the hyperbolic limit, at which collision and electric-field terms dominate the other terms in the Boltzmann equation. The reduced equation is of the drift-diffusion type, but it includes additional terms, and diffusion and drift do not obey the Einstein relation except in the limit of high temperatures.
- Received 20 August 2003
DOI:https://doi.org/10.1103/PhysRevB.68.241304
©2003 American Physical Society