Posner Molecule's Asymmetric Spin Dynamics Challenges Quantum Coherence Model — E8 Intelligence Research

Andrew Stewart Caldin

Published Oct 21, 2026• 0 citations

Abstract

FINDING: Posner molecule (Ca₉(PO₄)₆) proposed as biological quantum information processor; recent arXiv analysis shows its dynamical ensemble is *not* symmetric, challenging assumptions of long-lived nuclear spin coherence. | MATH: Stoichiometry Ca₉(PO₄)₆ → 9 Ca²⁺, 6 PO₄³⁻; nuclear spins: ³¹P (I=1/2), ⁴³Ca (I=7/2); proposed quantum error-correcting code dimension d = 2³ = 8 (3 phosphate qubits); Fisher's model requires spin‑spin coupling J ≫ decoherence rate Γ, with coherence time τ_Q > 10⁻³ s at 300 K. The arXiv paper (2108.08822) computes the dynamical Lie algebra of the spin Hamiltonian; finds it does *not* close to full SU(8) — the ensemble's symmetry group is a proper subgroup, reducing accessible Hilbert space dimension. | CONNECTION: Ca₉(PO₄)₆ crystal structure: rhombohedral (R3c space group), Ca²⁺ sites form a distorted octahedral arrangement around PO₄ tetrahedra. The 9 Ca positions map to a 3×3 grid — a rank‑2 root system (A₂) lattice projection. The phosphate tetrahedra (T_d Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com

DOI: 10.5281/zenodo.23525678

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