χR(∣T5⟩⊗1) ≤ 3

Tâ‚… orbit, ququint.

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   t5_m1_stabRankP_le_three in LeanProofs.T5M1StabRank, machine-checked by Lean

Implied per-copy exponent γ ≤ 0.6826 against a baseline 0.6826 (single-copy product bound; no published exponent), no improvement.

Lean proof

This bound is backed by a machine-checked theorem: t5_m1_stabRankP_le_three in LeanProofs.T5M1StabRank. The recorded lake build confirms it compiles.

Compute

1 run; 0.001 CPU-hours; 0.001 h wall-clock; on Apple silicon laptop, one core.

Notes

|T5⟩ = 5^(-1/2) sum_x w5^(x^3) |x⟩ is a combination of |0⟩, |1⟩ and the full-support state 5^(-1/2) sum_y w5^(4y^2 + 4y) |y⟩, with the coefficients above recovered exactly by fit_coeffs.fit from the normal equations and the identity checked symbolically by the verifier. The pivot search lists ten rank-3 decompositions over the 30 single-ququint states in all. With the exact rank-2 exclusion of cert_t5_m1_rank2.py this settles χ(|T5⟩) = 3, which is below the local dimension, unlike T3 where χ(|T3⟩) = 3 = p. The implied γ log_5(3) = 0.6826 is the single-copy product bound; no exponent has been published for any p = 5 state, so it is the baseline the orbit is measured against.

Attribution

this repository · stabrank docs/notes/new_orbits_design.md · pivot search over the 30 single-ququint stabilizer states, then exact refit with fit_coeffs.fit

Submission

JSON
{
  "schema_version": "0.1",
  "orbit": "T5",
  "m": 1,
  "direction": "upper",
  "rank": 3,
  "witness": {
    "terms": [
      {
        "k": 0,
        "x0": [
          0
        ],
        "W": [],
        "Q": [],
        "l": []
      },
      {
        "k": 0,
        "x0": [
          1
        ],
        "W": [],
        "Q": [],
        "l": []
      },
      {
        "k": 1,
        "x0": [
          0
        ],
        "W": [
          [
            1
          ]
        ],
        "Q": [
          [
            4
          ]
        ],
        "l": [
          4
        ]
      }
    ],
    "coeffs": [
      "-1/4 + sqrt(5)/4 + I*sqrt(sqrt(5)/40 + 1/8)",
      "1/2 + I*sqrt(1/4 - sqrt(5)/10)",
      "-1/4 + sqrt(5)/4 - I*sqrt(sqrt(5)/8 + 5/8)"
    ]
  },
  "provenance": {
    "author": "this repository",
    "reference": "stabrank docs/notes/new_orbits_design.md",
    "method": "pivot search over the 30 single-ququint stabilizer states, then exact refit with fit_coeffs.fit",
    "date": "2026-09-20",
    "github": [
      "vprusso"
    ],
    "compute": {
      "cpu_hours": 0.001,
      "wall_clock_hours": 0.001,
      "runs": 1,
      "hardware": "Apple silicon laptop, one core"
    }
  },
  "notes": "|T5> = 5^(-1/2) sum_x w5^(x^3) |x> is a combination of |0>, |1> and the full-support state 5^(-1/2) sum_y w5^(4y^2 + 4y) |y>, with the coefficients above recovered exactly by fit_coeffs.fit from the normal equations and the identity checked symbolically by the verifier. The pivot search lists ten rank-3 decompositions over the 30 single-ququint states in all. With the exact rank-2 exclusion of cert_t5_m1_rank2.py this settles chi(|T5>) = 3, which is below the local dimension, unlike T3 where chi(|T3>) = 3 = p. The implied gamma log_5(3) = 0.6826 is the single-copy product bound; no exponent has been published for any p = 5 state, so it is the baseline the orbit is measured against.",
  "lean": {
    "module": "LeanProofs.T5M1StabRank",
    "theorem": "t5_m1_stabRankP_le_three"
  }
}