{
 "schema_version": "0.2",
 "name": "[[25,1,5]] surface code",
 "code_type": "CSS",
 "n": 25,
 "k": 1,
 "checks": {
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   [
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   [
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   [
    15,
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   [
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   [
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   [
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 },
 "distance": {
  "d": 5,
  "X": {
   "value": 5,
   "confidence": "exact",
   "witness": [
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    3,
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  },
  "Z": {
   "value": 5,
   "confidence": "exact",
   "witness": [
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    5,
    10,
    16,
    21
   ]
  }
 },
 "provenance": {
  "authors": [
   "Kitaev, A. Yu."
  ],
  "origin": "baseline",
  "construction": "Rotated surface code, distance 5.",
  "date": "1997-07-09",
  "references": [
   "arXiv:quant-ph/9707021"
  ],
  "notes": "Distance is exact by construction. 2D layout added 2026-07-23: qubit q at (q//5, q%5) on the 5x5 planar grid; single layer, measured interaction radius sqrt(2)."
 },
 "family": "topological",
 "locality": {
  "coordinates": [
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   ],
   [
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   [
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   [
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   [
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   [
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   [
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   ],
   [
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   ],
   [
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   [
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  "interaction_radius": 1.4142135623730951,
  "layers": 1
 },
 "circuit": {
  "d_circ": {
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    "value": 5,
    "confidence": "upper_bound",
    "witness": [
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   "X": {
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    "confidence": "upper_bound",
    "witness": [
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   }
  },
  "rounds": 5,
  "stim_version": "1.16.0",
  "notes": "standard geometric zigzag schedule (X pattern 'n', Z pattern 'z') derived from the 2D layout; generated by research/circuit_seed.py",
  "ler": {
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    "p": 0.001,
    "shots": 100000,
    "failures": 150,
    "seed": 7,
    "decoder": "bposd-cs-10",
    "ler_per_round": 0.000300361,
    "ci95": [
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   "Z": {
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    "shots": 100000,
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    "seed": 7,
    "decoder": "bposd-cs-10",
    "ler_per_round": 0.000254258,
    "ci95": [
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   }
  }
 }
}