title: Wave fronts may move upstream in semiconductor superlattices
abstract: In weakly coupled, current biased, doped semiconductor superlattices, domain walls may move upstream against the flow of electrons. For appropriate doping values, a domain wall separating two electric-field domains moves downstream below a first critical current, it remains stationary between this value and a second critical current, and then moves upstream above. These conclusions are reached by using a comparison principle to analyze a discrete drift-diffusion model, and validated by numerical simulations. Possible experimental realizations are suggested.
authors.affiliation: Departamento de Matematica Aplicada, Universidad Complutense, Madrid, Spain.
authors.initials: A
authors.lastname: Carpio
authors.initials: LL
authors.lastname: Bonilla
authors.initials: A
authors.lastname: Wacker
authors.initials: E
authors.lastname: Scholl