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    "headline": "Local Tests Reached Constant Rate and Distance",
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    "dek": "An explicit qubit-code construction combines constant rate, constant relative distance and constant-soundness local tests.",
    "summary": "An explicit qubit-code construction combines constant rate, constant relative distance and constant-soundness local tests.",
    "body_text": "Quantum locally testable codes aim to diagnose global encoding errors through checks that touch only a constant number of qubits. This work gives explicit qubit-based quantum LDPC CSS code families that are asymptotically good: their information rate and relative distance remain constant as the code grows. Their testers also keep constant weight and constant soundness. The result is a mathematical construction rather than a hardware demonstration, but it closes a central combination of parameters for locally testable quantum error correction.",
    "why_it_matters": "An explicit qubit-code construction combines constant rate, constant relative distance and constant-soundness local tests.",
    "limitations": [
      "Quantum locally testable codes aim to diagnose global encoding errors through checks that touch only a constant number of qubits.",
      "This work gives explicit qubit-based quantum LDPC CSS code families that are asymptotically good: their information rate and relative distance remain constant as the code grows."
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    "first_published_at": "2026-09-18T09:00:00.000-04:00",
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    "tags": [
      "quantum error correction",
      "LDPC codes",
      "local testing"
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      "source_id": "source-2026-09-18-013",
      "title": "arXiv preprint 2609.20780",
      "publisher": "arXiv",
      "url": "https://arxiv.org/abs/2609.20780",
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      "published_at": "2026-09-17T13:49:39.000-04:00",
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    "name": "The Machine Press",
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  "cite_this_report": {
    "title": "Local Tests Reached Constant Rate and Distance",
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    "published_at": "2026-09-18T09:00:00.000-04:00",
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