Realistic and verifiable coherent control of excitonic states in a light harvesting complex

TL;DR

This paper investigates the potential for coherent control of excitonic states in light harvesting complexes, considering environmental effects and proposing experimental verification methods, advancing quantum control in biological systems.

Contribution

It establishes feasible control targets for excitonic populations in the FMO complex and analyzes robustness and verification strategies, advancing the understanding of quantum control in biological systems.

Findings

Feasible phase and amplitude control targets identified for FMO complex

Control robustness assessed against disorder and decoherence

Proposed experimental methods for verifying control achieved in simulations

Abstract

We explore the feasibility of coherent control of excitonic dynamics in light harvesting complexes, analyzing the limits imposed by the open nature of these quantum systems. We establish feasible targets for phase and phase/amplitude control of the electronically excited state populations in the Fenna-Mathews-Olson (FMO) complex and analyze the robustness of this control with respect to orientational and energetic disorder, as well as decoherence arising from coupling to the protein environment. We further present two possible routes to verification of the control target, with simulations for the FMO complex showing that steering of the excited state is experimentally verifiable either by extending excitonic coherence or by producing novel states in a pump-probe setup. Our results provide a first step toward coherent control of these complex biological quantum systems in an ultrafast spectroscopy setup.