Posner Molecule's Asymmetric Dynamics Undermine Quantum Coherence Proposal — E8 Intelligence Research

Andrew Stewart Caldin

Published Sep 27, 2026• 0 citations

Abstract

FINDING: Posner molecule (Ca₉(PO₄)₆) proposed as biological quantum information processor; recent arXiv paper (2108.08822v2) shows its dynamical ensemble is *not* symmetric, undermining a key assumption for long-lived nuclear spin coherence. | MATH: Posner molecule stoichiometry: Ca₉(PO₄)₆ → 9 Ca²⁺, 6 PO₄³⁻. Nuclear spin-1/2 on ³¹P (6 per molecule). Proposed quantum error-correcting code: ³¹P nuclear spins encode logical qubits via dipole-dipole couplings; symmetry group of the molecule's rotational degrees of freedom (point group T_d or C₃ᵥ, depending on conformation) was assumed to protect against decoherence. The paper's key result: the dynamical ensemble (time-averaged density matrix ρ̄ = ∫ U(t)ρU†(t) dt) does *not* possess the full point-group symmetry, so the protected subspace dimension is smaller than claimed. Specifically, the commutator [H_dip, R] ≠ 0 for some symmetry operation R, breaking the previously assumed invariant subspace. | CONNECTION: The molecule's phosphate tetr Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com

DOI: 10.5281/zenodo.22987177

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