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    "headline": "A Diamond Spin Ensemble Revealed Its Own Projection Noise",
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    "dek": "Nuclear-memory readout improved fidelity nearly tenfold and resolved interaction-driven anisotropy.",
    "summary": "Nuclear-memory readout improved fidelity nearly tenfold and resolved interaction-driven anisotropy.",
    "body_text": "A two-dimensional nitrogen-vacancy ensemble in diamond was read repeatedly through intrinsic nitrogen-15 nuclear memory at about 0.3 tesla. The method improved readout fidelity by nearly an order of magnitude, enough to resolve coherent-state quantum projection noise and watch dipolar interactions shear it into an anisotropic profile. The experiment opens a route toward directly measuring spin squeezing and entanglement-enhanced sensing, but does not report those later sensing gains yet.",
    "why_it_matters": "Nuclear-memory readout improved fidelity nearly tenfold and resolved interaction-driven anisotropy.",
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      "The experiment opens a route toward directly measuring spin squeezing and entanglement-enhanced sensing, but does not report those later sensing gains yet."
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        "qualification": "The experiment opens a route toward directly measuring spin squeezing and entanglement-enhanced sensing, but does not report those later sensing gains yet."
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    "source_ids": [
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    "tags": [
      "quantum sensing",
      "diamond NV centers",
      "projection noise"
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  "sources": [
    {
      "source_id": "source-2026-09-16-018",
      "title": "arXiv preprint 2609.16106",
      "publisher": "arXiv",
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      "published_at": "2026-09-14T20:00:00.000-04:00",
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    "title": "A Diamond Spin Ensemble Revealed Its Own Projection Noise",
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