Sustainability of environment-assisted energy transfer in quantum photobiological complexes

TL;DR

This paper demonstrates that environment-assisted energy transfer in photobiological complexes exhibits quantum sustainability, enabling long-lived quantum coherence, reduced entropy, and enhanced energy transfer efficiency, which are crucial for biological function.

Contribution

It introduces the concept of quantum sustainability in PBCs and models it using non-Hermitian Hamiltonians, revealing long-lived quantum coherence and improved energy transfer.

Findings

Quantum sustainability is a universal phenomenon in PBCs.

Sustainable models predict long-lasting quantum coherence.

Sustainable evolution reduces entropy and enhances EET efficiency.

Abstract

It is shown that quantum sustainability is a universal phenomenon which emerges during environment-assisted electronic excitation energy transfer (EET) in photobiological complexes (PBCs), such as photosynthetic reaction centers and centers of melanogenesis. We demonstrate that quantum photobiological systems must be sustainable for them to simultaneously endure continuous energy transfer and keep their internal structure from destruction or critical instability. These quantum effects occur due to the interaction of PBCs with their environment which can be described by means of the reduced density operator and effective non-Hermitian Hamiltonian (NH). Sustainable NH models of EET predict the coherence beats, followed by the decrease of coherence down to a small, yet non-zero value. This indicates that in sustainable PBCs, quantum effects survive on a much larger time scale than the energy relaxation of an exciton. We show that sustainable evolution significantly lowers the entropy of PBCs and improves the speed and capacity of EET.