Decoherence in electron transport: back-scattering, effect on interference and rectification

TL;DR

This paper investigates how partial decoherence affects electron transport in quantum wires and rings, revealing backscattering, rectification, and suppression of quantum interference effects due to dephasing.

Contribution

It demonstrates the impact of local dephasing on backscattering, rectification, and quantum interference, providing new insights into decoherence effects in mesoscopic systems.

Findings

Decoherence causes backscattering in ballistic channels.

Rectification occurs when a local dephasing center and impurity break inversion symmetry.

Quantum interference effects like Fabry-Pérot oscillations are suppressed by decoherence.

Abstract

Decoherence is an undesirable, but ubiquitous phenomenon in quantum systems. Here, we study the effect of partial decoherence, induced via a B\"uttiker probe, on two-terminal electronic transport across one-dimensional quantum wires and rings, in both the linear and non-linear regimes. We find that dephasing causes backscattering when introduced locally in a ballistic channel. Further, we find that decoherence results in rectification when inversion is broken in the two-terminal transport set-up by a combination of a local dephasing centre and a static impurity. Interestingly, the rectification strength and even its direction varies strongly with the relative distance between the probe and the scatterer. We further analyze how decoherence affects characteristic quantum effects in electronic transport, such as, Fabry-P\'erot oscillations in double-barrier setups, and Aharonov-Bohm interference in one-dimensional rings, and find that the amplitude of oscillations in conductance is reduced by decoherence.