Ambient-Temperature Quantum Coherence in FMO Enables Near-Unity Photosynthetic Energy Transfer — E8 Intelligence Research

FINDING: Photosynthetic exciton transport sustains quantum coherence at ambient temperature via a Fenna–Matthews–Olson (FMO) pigment-protein complex, enabling near-unity energy transfer efficiency across ~10 nm. MATH: - Exciton Hamiltonian: H = Σᵢ εᵢ|i⟩⟨i| + Σᵢⱼ Jᵢⱼ|i⟩⟨j|, with site energies εᵢ and dipole-dipole couplings Jᵢⱼ ∝ (dᵢ·dⱼ − 3(dᵢ·r̂)(dⱼ·r̂))/r³ - Coherence lifetime τ_coh ~ 300–660 fs at 77 K; ~50–100 fs at 300 K (Engel et al. 2007; Panitchayangkoon et al. 2010) - Energy transfer efficiency η ≈ 0.95–0.99 (near-unity) - Dephasing rate γ_φ ~ 1/τ_coh; Redfield tensor governs relaxation - 2D electronic spectroscopy: oscillatory cross-peaks at frequencies ω = (εᵢ − εⱼ)/ℏ reveal electronic coherence beats - Coupling strength: J ~ 20–100 cm⁻¹; reorganization energy λ ~ 35–200 cm⁻¹ CONNECTION: - FMO complex is a trimer (C3 symmetry) — 3-fold rotational crystallographic symmetry, each monomer containing 7 bacteriochlorophyll a sites (7 = prime, no direct φ link) - Site geometry a Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com