{"paper":{"title":"The most discriminable quantum states in the multicopy regime","license":"http://creativecommons.org/licenses/by/4.0/","headline":"For large enough N, state k-designs exactly maximize success probability in multi-copy pure-state discrimination.","cross_cats":[],"primary_cat":"quant-ph","authors_text":"Lucas B. Vieira, Lucas E. A. Porto, Marco T\\'ulio Quintino, Maria Kvashchuk, Polina Chernyshova, Ties-A. Ohst","submitted_at":"2026-04-29T17:41:12Z","abstract_excerpt":"This work investigates which sets of quantum states give rise to the highest achievable success probability in minimum-error state discrimination if multiple copies of the unknown state are given. Specifically, we consider uniformly distributed ensembles of the form $\\left\\{\\frac{1}{N},\\rho_i^{\\otimes k}\\right\\}_{i=1}^N$, where $N$ states in dimension $d$ are provided in $k$ identical copies, and derive universal limits in this scenario. For pure state ensembles, we prove that whenever $N$ is large enough to support a state $k$-design, these designs will exactly give rise to the maximally disc"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"For pure state ensembles, we prove that whenever N is large enough to support a state k-design, these designs will exactly give rise to the maximally discriminable sets.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The assumption that the ensemble is uniformly distributed and that k-designs exist with the required symmetry properties for the given dimension d and copy number k.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"k-designs achieve maximal discriminability for pure states in multi-copy minimum-error discrimination; mixed states outperform for larger ensembles, with quantum offering quadratic advantage over classical.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"For large enough N, state k-designs exactly maximize success probability in multi-copy pure-state discrimination.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"1619049d142661892788809358752ea5b23866ef3bef26888b7abf0381222f9a"},"source":{"id":"2604.26927","kind":"arxiv","version":2},"verdict":{"id":"e3a7f136-7918-4cee-917b-21ac04cb31cd","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-07T09:58:03.684083Z","strongest_claim":"For pure state ensembles, we prove that whenever N is large enough to support a state k-design, these designs will exactly give rise to the maximally discriminable sets.","one_line_summary":"k-designs achieve maximal discriminability for pure states in multi-copy minimum-error discrimination; mixed states outperform for larger ensembles, with quantum offering quadratic advantage over classical.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The assumption that the ensemble is uniformly distributed and that k-designs exist with the required symmetry properties for the given dimension d and copy number k.","pith_extraction_headline":"For large enough N, state k-designs exactly maximize success probability in multi-copy pure-state discrimination."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2604.26927/integrity.json","findings":[],"available":true,"detectors_run":[{"name":"ai_meta_artifact","ran_at":"2026-05-20T23:37:01.566458Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"doi_compliance","ran_at":"2026-05-19T19:42:27.447411Z","status":"completed","version":"1.0.0","findings_count":0}],"snapshot_sha256":"c36f4f84568f8a043a43f2b494fd8e97c93d32dd286c828f0da7f44ad7374e97"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}