Steady state current transfer and scattering theory

TL;DR

This paper explores the relationship between steady state current transfer and scattering theory in coupled tight-binding models, analyzing effects of decoherence and impurity scattering on transmission and transfer efficiency.

Contribution

It establishes the connection between current transfer and scattering theory in 1D wire models and examines decoherence effects using a generalized Liouville-von Neumann approach.

Findings

Weak interwire coupling yields similar results in both theories.

Dephasing reduces current transfer efficiency.

Impurity energy position affects transmission under decoherence.

Abstract

The correspondence between the steady state theory of current transfer and scattering theory in a system of coupled tight-binding models of 1-dimensional wires is explored. For weak interwire coupling both calculations give nearly identical results, except at singular points associated with band edges. The effect of decoherence in each of these models is studied using a generalization of the Liouville-von Neuman equation suitable for steady-state situations. An example of a single impurity model is studied in details, leading to a lattice model of scattering off target that affects both potential scattering and decoherence. For an impurity level lying inside the energy band, the transmission coefficient diminishes with increasing dephasing rate, while the opposite holds for impurity energy outside the band. The efficiency of current transfer in the coupled wire system decreases with increasing dephasing.