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    "headline": "Topological Codes Gained a Proven Coherent-Error Threshold",
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    "dek": "A cluster-expansion proof covers bounded logical-qubit quantum LDPC codes, including the surface code.",
    "summary": "A cluster-expansion proof covers bounded logical-qubit quantum LDPC codes, including the surface code.",
    "body_text": "Unlike random Pauli faults, coherent rotations can interfere across many error paths. The proof retains those amplitudes with Fourier analysis and combines them with a polymer-model cluster expansion. Below a code-size-independent rotation bound, maximum-likelihood Pauli recovery suppresses entanglement infidelity exponentially in distance, up to a prefactor linear in physical qubits.",
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    "tags": [
      "surface code",
      "coherent errors",
      "threshold theorem"
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      "title": "arXiv preprint 2609.20708",
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    "title": "Topological Codes Gained a Proven Coherent-Error Threshold",
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