Quantum Dynamics of Spin Transport in Photosynthetic Reaction Centers


Quantum biology is a new swiftly growing scientific synthesis merging quantum information science with the richness and complexity of biological systems.

Recent theoretical and experimental evidence supports the early intuition of the founding fathers of quantum mechanics that biological systyems should be influenced by the intricacies of quantum physics. Currently, quantum biology is explored mainly along three fronts: photosynthesis, magnetoreception and olfaction.Quantum biology is not about the “static”, atomistic aspect of biological structure but about dynamic effects related to quantum coherence and entanglement influencing biological function. Quantum biology is a uniquely interdisciplinary field combining quantum science, physical chemistry, biochemistry and biology.

Quantum Dynamics in Photosynthetic Reaction Centers

Our contributions

We were one among the few groups that pioneered the field of quantum biology. We introduced the study of the fundamental quantum dynamics of the radical-pair mechanism. Radical-ion-pair reactions are spin-dependent biochemical reactions relevant to photosynthesis and the avian magnetic compass. This work is briefly outlined in the Section Quantum Foundations of the Radical-Pair Mechanism.

Here we describe another front of this research related to photosynthesis. Radical-ion-pair reactions regulate spin-transport in photosynthetic reaction centers. Such transport produces highly non-equilibrium nuclear spin polarizations, which can serve to unravel the reaction center’s structure with NMR studies. 

The paradigm shift we introduced in the fundamental understanding of radical-pair reactions has its most severe manifestation in the quantitative understanding of CIDNP data (Chemically Induced Dynamic Nuclear Polarization). We have shown that the theoretical interpretation of CIDNP data can lead to discrepancies of an order of magnitude when using the traditional approach to radical-pair spin dynamics.