Asymmetric Posner Ensemble Challenges Proposed Long-Lived Nuclear Spin Qubit — E8 Intelligence Research

FINDING: Posner molecule (Ca₉(PO₄)₆) quantum coherence evidence is contested; the dynamical ensemble is explicitly *not* symmetric, undermining the proposed long-lived nuclear spin qubit mechanism. | MATH: Molecular formula Ca₉(PO₄)₆; nuclear spin quantum number I=1/2 for ³¹P; proposed coherence time τ ~ 10⁵ s (theoretical); symmetry breaking quantified by non-zero anisotropic tensor components in the nuclear magnetic resonance (NMR) Hamiltonian — specifically, the quadrupolar coupling constant C_Q ≠ 0 for ⁴³Ca (I=7/2) and dipolar coupling between ³¹P spins. The paper (arXiv:2108.08822v2) shows the dynamical ensemble average of the spin Hamiltonian lacks the full T_d (tetrahedral) or S_6 symmetry previously assumed, reducing the effective Hilbert space dimension from 2⁶ = 64 to a smaller, symmetry-broken subspace. | CONNECTION: The claimed geometric harmony is *broken*: the ideal Posner cluster has approximate octahedral (O_h) or tetrahedral (T_d) symmetry — related to the root system Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com