Adaptive Stabilizer State Fidelity Certification
Abstract
Certifying the fidelity of a prepared state to a target stabilizer state is a fundamental task in quantum information processing. Ref. [Phys. Rev. A 99, 042337 (2019)] gave the optimal worst-case lower bound from one fixed stabilizer generator gauge, but gauge dependence can leave a large fidelity ambiguity. We develop an adaptive extension that reports the full certified fidelity interval. First, for a single gauge, we derive the complementary optimal worst-case upper bound. We then formulate gauge selection as an adaptive design problem in which each round solves exact endpoint linear programs and chooses a new gauge by a witness elimination policy. We prove monotonic tightening, exact recovery once all nontrivial stabilizers are covered, and the worst-case necessity of full coverage. Finally, we identify structured syndrome distributions for which adaptivity beats this exponential benchmark, and we numerically confirm faster concentration.
Comments: 24 pages, 5 figures and 2 tables. Comments are welcome
Cite
@article{arxiv.2605.29820,
title = {Adaptive Stabilizer State Fidelity Certification},
author = {Kun Wang},
journal= {arXiv preprint arXiv:2605.29820},
year = {2026}
}