The problem of phase breaking in the electronic conduction in mesoscopic systems: a linear-response theory approach

TL;DR

This paper investigates how phase-breaking scatterers affect electronic conduction in mesoscopic systems using linear-response theory, highlighting the reduction of coherence and providing a model for zero-temperature conductance.

Contribution

It introduces a linear-response framework incorporating phase breakers with internal degrees of freedom, extending understanding of mesoscopic conductance beyond static impurity models.

Findings

Phase breakers reduce coherent interference effects.

Conductance depends on transmission coefficients including phase breaker states.

Model links zero-temperature conductance to transmission with phase-breaking effects.

Abstract

We study the problem of electronic conduction in mesoscopic systems when the electrons are allowed to interact not only with static impurities, but also with a scatterer (a phase breaker(PB)) that possesses internal degrees of freedom. We first analyze the role of the PB in reducing the coherent interference effects in a one-electron quantum-mechanical system. In the many-electron system we can make a number of quite general statements within the framework of linear-response theory and the random-phase approximation. We cannot calculate the conductivity tensor in full generality: we thus resort to a model, in which that tensor can be expressed entirely in a single-electron picture. The resulting zero-temperature conductance can be written in terms of the total transmission coefficient at the Fermi energy, containing an additional trace over the states of the PB.