Environment-assisted quantum transport in ordered systems

TL;DR

This paper explores how environmental noise can enhance quantum transport efficiency in ordered systems, revealing new mechanisms beyond disorder-induced effects, with implications for energy transfer in biological systems.

Contribution

It introduces novel mechanisms of environment-assisted quantum transport in ordered systems, expanding understanding beyond disordered models and applicable to various quantum transport scenarios.

Findings

Identifies new environment-assisted transport mechanisms in ordered systems.

Demonstrates that noise can improve transport efficiency even without disorder.

Provides a general model relevant to biological and artificial quantum systems.

Abstract

Noise-assisted transport in quantum systems occurs when quantum time-evolution and decoherence conspire to produce a transport efficiency that is higher than what would be seen in either the purely quantum or purely classical cases. In disordered systems, it has been understood as the suppression of coherent quantum localisation through noise, which brings detuned quantum levels into resonance and thus facilitates transport. We report several new mechanisms of environment-assisted transport in ordered systems, in which there is no localisation to overcome and where one would naively expect that coherent transport is the fastest possible. Although we are particularly motivated by the need to understand excitonic energy transfer in photosynthetic light-harvesting complexes, our model is general---transport in a tight-binding system with dephasing, a source, and a trap---and can be expected to have wider application.