Quantum Coherence in Photosynthetic Energy Transfer

In natural photosynthesis, light-harvesting complexes capture solar photons and funnel excitation energy to reaction centres with near-unity efficiency. Over the past two decades, evidence has emerged that quantum coherence – the wavelike superposition of electronic states – may play an active role in guiding energy through pigment–protein networks. These coherent phenomena allow excitations (excitons) to explore multiple pathways simultaneously, potentially bypassing energetic bottlenecks. Ambient biological environments, however, introduce vibrational dynamics and noise that tend to destroy coherence on ultrafast timescales. Recent research has therefore focused on uncovering mechanisms that sustain or even harness coherence despite environmental fluctuations. Advanced spectroscopic techniques, model systems and theoretical frameworks now converge to reveal how vibronic coupling, phase synchronisation and environment-assisted transport work in concert to protect coherent energy flow. These interdisciplinary insights bear global significance for the design of biomimetic light-harvesting materials and quantum devices that emulate nature’s efficiency.

Research from Nature Portfolio

Recent studies have demonstrated that single-photon excitation under ambient conditions can initiate coherent energy transfer in a bacterial light-harvesting complex. By correlating single-photon absorption with subsequent emission, experiments confirm that individual quanta drive ultrafast electronic energy transfer between pigment rings, underscoring the genuine quantum nature of the process. Complementary work on photosynthetic antennas has uncovered that resonant vibrational modes of excitonic dimers can undergo phase synchronisation. This selective dissipation suppresses anti-symmetric vibrations while preserving symmetric modes, prolonging exciton–vibrational coherence by up to an order of magnitude. Foundational experiments with artificial molecular light harvesters have further pinpointed vibronic coupling between electronic transitions and specific vibrational modes as a key origin of long-lived coherence. Together, these findings delineate a continuum from single-photon events to collective vibronic mechanisms that protect quantum coherence in complex pigment networks.

Quantum Coherence in Photosynthetic Energy Transfer publication trend

The graph below shows the total number of articles in quantum coherence in photosynthetic energy transfer across all publications each year (not limited to Nature Index journals).

Technical terms

Quantum coherence: The superposition of electronic states enabling wavelike energy transfer across pigments.

Exciton: A delocalised electronic excitation shared among coupled chromophores.

Vibronic coupling: Interaction between electronic transitions and molecular vibrational modes.

Dephasing: The process by which environmental interactions diminish quantum coherence.

Two-dimensional electronic spectroscopy: An ultrafast technique that correlates excitation and emission frequencies to map coherent dynamics.

References

1. Single-photon absorption and emission from a natural photosynthetic complex. Nature (2023).
2. Quantum phase synchronization via exciton-vibrational energy dissipation sustains long-lived coherence in photosynthetic antennas. Nature Communications (2024).
3. Protein-Based Model for Energy Transfer between Photosynthetic Light-Harvesting Complexes Is Constructed Using a Direct Protein–Protein Conjugation Strategy. Journal of the American Chemical Society (2023).
4. Environment-assisted quantum transport. New Journal of Physics (2009).
5. Vibronic origin of long-lived coherence in an artificial molecular light harvester. Nature Communications (2015).