Unified description of coherent and dissipative electron transport.

Abstract

We apply the Landauer-B\"uttiker theory of dc electron transport to a chain of scatterers, which are coupled to an external heat bath. In this approach, coherent and dissipative transport are treated in a unified manner, and the suppression of quantum coherence effects for increasing coupling with the heat bath can be described. In particular, we find that the resonant behavior of the conductance with respect to the Fermi wave vector disappears gradually with increasing coupling. For intermediate coupling, resonance effects are only found for sufficiently small samples. They disappear asymptotically with increasing sample size. The characteristic length for this dephasing effect corresponds to the mean free path, which is derived from the exponential decay of the transmission coefficient in the presence of inelastic scattering.