verified 7 stabilizer terms reproduce |qubit_H>^{ot 6}, checked symbolically
Implied per-copy exponent γ ≤ 0.4679 against a published 0.3962, no improvement.
3 runs; 0.1 CPU-hours; 0.1 h wall-clock; on Apple silicon laptop, 8 annealing chains per run.
The six-copy value of Bravyi, Smith, and Smolin, χ(|H⟩⊗6) ≤ 7, behind the 2^{0.47n} figure (log_2(7)/6 = 0.468); they conjectured it optimal, and Qassim, Pashayan, and Gosset later gave rank 6, which is the cell's record. Kept on the ledger as the historical value with a witness: found here by the package's annealer (search_decomposition.py, target qubit_real, seed 3, starting rank 7) and verified in exact arithmetic. Two runs starting at rank 6 (seeds 1 and 2) both stopped at residual 0.101, so the annealer did not find the rank-6 cat-state decomposition on its own.
Bravyi, Smith, and Smolin · arXiv:1506.01396 · literature
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"sqrt(2)/4",
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"sqrt(2)/4",
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"provenance": {
"author": "Bravyi, Smith, and Smolin",
"reference": "arXiv:1506.01396",
"method": "literature",
"date": "2015-06-03",
"github": [],
"compute": {
"cpu_hours": 0.1,
"wall_clock_hours": 0.1,
"runs": 3,
"hardware": "Apple silicon laptop, 8 annealing chains per run"
}
},
"notes": "The six-copy value of Bravyi, Smith, and Smolin, chi(|H>^6) <= 7, behind the 2^{0.47n} figure (log_2(7)/6 = 0.468); they conjectured it optimal, and Qassim, Pashayan, and Gosset later gave rank 6, which is the cell's record. Kept on the ledger as the historical value with a witness: found here by the package's annealer (search_decomposition.py, target qubit_real, seed 3, starting rank 7) and verified in exact arithmetic. Two runs starting at rank 6 (seeds 1 and 2) both stopped at residual 0.101, so the annealer did not find the rank-6 cat-state decomposition on its own."
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