χ_R(∣N⟩^⊗2) ≤ 3

Norrell orbit, qutrit.

Participate

Run it yourself, or point a coding agent at it.

git clone https://github.com/unitaryfoundation/stabrank
cd stabrank
# describe your decomposition in bounds/mybound.json
make fit BOUND=bounds/mybound.json ARGS=--write
make verify BOUND=bounds/mybound.json

fit solves for the exact coefficients, or tells you no exact combination of your terms reproduces the target. verify rebuilds the identity in exact arithmetic. If it passes, open a pull request adding the file and the leaderboard picks it up on the next build.

A bound the pipeline cannot check is recorded as cited and never takes a record.

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Verification

lean norrell_m2_stabRank_le_three in LeanProofs.M2StabRank, machine-checked by Lean

Implied per-copy exponent γ ≤ 0.5000 against a published 0.4206, no improvement.

Lean proof

This bound is backed by a machine-checked theorem: norrell_m2_stabRank_le_three in LeanProofs.M2StabRank. The recorded lake build confirms it compiles.

Notes

Now stated against stabRank: norrell_m2_stabRank_le_three proves Stabilizer.stabRank IsStab |N⟩^⊗2 ≤ 3 with the three terms shown to be stabilizer states in the concrete sense (full support with phase y0 + y1 + y0 y1, the point |2,2>, and full support with twice that phase). With the rank-2 exclusion certificate the cell is settled at 3.

Attribution

Labib and Russo · arXiv:2605.28586 · literature

Submission

JSON

{
  "schema_version": "0.1",
  "orbit": "N",
  "m": 2,
  "direction": "upper",
  "rank": 3,
  "provenance": {
    "author": "Labib and Russo",
    "reference": "arXiv:2605.28586",
    "method": "literature",
    "date": "2026-05-27",
    "github": [
      "FarLab",
      "vprusso"
    ]
  },
  "notes": "Now stated against stabRank: norrell_m2_stabRank_le_three proves Stabilizer.stabRank IsStab |N>^2 <= 3 with the three terms shown to be stabilizer states in the concrete sense (full support with phase y0 + y1 + y0 y1, the point |2,2>, and full support with twice that phase). With the rank-2 exclusion certificate the cell is settled at 3.",
  "lean": {
    "module": "LeanProofs.M2StabRank",
    "theorem": "norrell_m2_stabRank_le_three"
  }
}