Stationary quantum coherence and transport in disordered networks

TL;DR

This paper investigates how quantum coherence influences excitation transport in disordered networks driven by incoherent light, revealing that coherent delocalization is essential for high efficiency, with implications for natural light-harvesting systems.

Contribution

It introduces a rigorous entanglement-based framework to analyze coherence in incoherently driven quantum networks, highlighting the importance of coherent delocalization for efficient transport.

Findings

Coherent delocalization over multiple sites enhances transport efficiency.

Quantum coherence plays a crucial role in excitation transfer under incoherent illumination.

The framework links quantum coherence to natural light-harvesting processes.

Abstract

We examine the excitation transport across quantum networks that are continuously driven by a constant and incoherent light source. In particular we investigate the coherence properties of incoherently driven networks by employing recent tools from entanglement theory that enable a rigorous interpretation of coherence in the site basis. With these tools at hand we identify coherent delocalization of excitations over several sites to be a crucial prerequisite for highly efficient transport across networks driven by an incoherent source. These results are set into context with the latest discussion of the occurrence and role of coherence in light-harvesting complexes that are exposed to natural incoherent sun light.