Dephasing assisted transport: Quantum networks and biomolecules

TL;DR

This paper demonstrates that local dephasing noise can enhance excitation transport in quantum networks and biomolecules, challenging the notion that environmental noise always impairs quantum transport.

Contribution

It reveals that dephasing noise can improve quantum transport efficiency at zero temperature and clarifies that entanglement is not necessary for this enhancement.

Findings

Dephasing noise enhances transport in quantum networks.

Entanglement is not essential for noise-assisted transport.

Biological systems like light-harvesting molecules benefit from this effect.

Abstract

Transport phenomena are fundamental in Physics. They allow for information and energy to be exchanged between individual constituents of communication systems, networks or even biological entities. Environmental noise will generally hinder the efficiency of the transport process. However, and contrary to intuition, there are situations in classical systems where thermal fluctuations are actually instrumental in assisting transport phenomena. Here we show that, even at zero temperature, transport of excitations across dissipative quantum networks can be enhanced by local dephasing noise. We explain the underlying physical mechanisms behind this phenomenon, show that entanglement does not play a supportive role and propose possible experimental demonstrations in quantum optics. We argue that Nature may be routinely exploiting this effect and show that the transport of excitations in light harvesting molecules does benefit from such noise assisted processes. These results point towards the possibility for designing optimized structures for transport, for example in artificial nano-structures, assisted by noise.