Environment-Assisted Quantum Transport

TL;DR

This paper shows that quantum transport efficiency at the nanoscale can be improved through a balance of quantum coherence and environmental noise, with implications for biological and disordered systems.

Contribution

It introduces the concept that environment-induced dephasing can enhance quantum transport, contrasting with traditional views of decoherence as purely detrimental.

Findings

Quantum transport is optimized by a balance of coherence and dephasing.

Disordered binary trees show improved transport with environmental noise.

Photosynthetic complexes benefit from environment-assisted energy transfer.

Abstract

Transport phenomena at the nanoscale are of interest due to the presence of both quantum and classical behavior. In this work, we demonstrate that quantum transport efficiency can be enhanced by a dynamical interplay of the system Hamiltonian with pure dephasing induced by a fluctuating environment. This is in contrast to fully coherent hopping that leads to localization in disordered systems, and to highly incoherent transfer that is eventually suppressed by the quantum Zeno effect. We study these phenomena in the Fenna-Matthews-Olson protein complex as a prototype for larger photosynthetic energy transfer systems. We also show that disordered binary tree structures exhibit enhanced transport in the presence of dephasing.