中文

Stabilizer rank bounds for magic-state orbits

量子物理 2026-05-28 v1

摘要

Distinct Clifford orbits of magic states can exhibit different stabilizer ranks at small tensor powers. We establish this for qutrits, where the single-qutrit Clifford group has four inequivalent orbits of magic states: Strange, Norrell, Hadamard-eigenstate, and the qutrit T-state, but a nontrivial upper bound on the asymptotic exponent had been pinned down for only the qutrit T-state. For the other three orbits we give explicit stabilizer decompositions, yielding upper bounds on the per-copy asymptotic stabilizer-rank exponent: γSlog3(2)/20.316\gamma_S \le \log_3(2)/2 \approx 0.316 for the Strange state, and γH3,γNlog3(4)/30.421\gamma_{H_3}, \gamma_N \le \log_3(4)/3 \approx 0.421 for the Hadamard-eigenstate and Norrell orbits, all strictly below the prior γT31/2\gamma_{T_3} \le 1/2 baseline. We also prove the first nontrivial Ω(m/logm)\Omega(m / \log m) asymptotic lower bounds for the Hadamard-eigenstate and Norrell orbits, and exhibit two-qutrit Clifford circuits that convert two copies of these states into an injectable phase state with constant success probability, enabling constant-overhead injection of one non-Clifford diagonal gate per orbit. In the case of qubits, we give a closed-form decomposition of the qubit T-type orbit at four copies matching the existing γTlog2(3)/40.396\gamma_T \le \log_2(3)/4 \approx 0.396 exponent via a direct algebraic identity rather than an entangled cat-state construction. An open-source library stabrank accompanies the paper, with Lean 4 proof formalizations of all the decompositions.

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引用

@article{arxiv.2605.28586,
  title  = {Stabilizer rank bounds for magic-state orbits},
  author = {Farrokh Labib and Vincent Russo},
  journal= {arXiv preprint arXiv:2605.28586},
  year   = {2026}
}