{"paper":{"title":"Scalable self-testing of generic multipartite quantum states","license":"http://creativecommons.org/licenses/by/4.0/","headline":"A protocol self-tests almost all n-qubit states robustly with only polynomial sample complexity.","cross_cats":[],"primary_cat":"quant-ph","authors_text":"Elias X. Huber, Jinchang Liu, Xingjian Zhang, Xiongfeng Ma, Zhenyu Du","submitted_at":"2026-05-14T17:23:40Z","abstract_excerpt":"Characterizing large quantum systems with minimal assumptions is a central challenge in quantum information science. Self-testing provides the strongest form of certification by identifying the underlying quantum state solely from observed measurement statistics. However, existing self-testing methods for generic $n$-partite states face a scalability barrier, requiring exponentially many samples in the system size. In this work, we overcome this barrier by introducing a protocol that robustly self-tests almost all $n$-qubit states with only polynomial sample complexity. The key ingredient is a"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"we overcome this barrier by introducing a protocol that robustly self-tests almost all n-qubit states with only polynomial sample complexity","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The efficient scheme for device-independently evaluating multipartite Pauli measurements can be implemented using only a linear number of ancillary Bell pairs together with standard projective and Bell measurements","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"A protocol self-tests generic n-qubit states with polynomial sample complexity via device-independent multipartite Pauli measurements implemented with linear Bell pairs.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"A protocol self-tests almost all n-qubit states robustly with only polynomial sample complexity.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"d2582459fa2a22b50d6110b9a8334aa5d31596c6370651218f9fea89555a3817"},"source":{"id":"2605.15106","kind":"arxiv","version":1},"verdict":{"id":"229f6bcb-2d87-4459-9732-8f7d50f63a65","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-15T03:01:05.677121Z","strongest_claim":"we overcome this barrier by introducing a protocol that robustly self-tests almost all n-qubit states with only polynomial sample complexity","one_line_summary":"A protocol self-tests generic n-qubit states with polynomial sample complexity via device-independent multipartite Pauli measurements implemented with linear Bell pairs.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The efficient scheme for device-independently evaluating multipartite Pauli measurements can be implemented using only a linear number of ancillary Bell pairs together with standard projective and Bell measurements","pith_extraction_headline":"A protocol self-tests almost all n-qubit states robustly with only polynomial sample complexity."},"references":{"count":36,"sample":[{"doi":"","year":null,"title":"Self-testing up toglobaltranspose We now remove the undesirable partial transpose terms in Lemma S3, thereby yielding a robust DI protocol that implements multipartite Pauli measurements up to only an","work_id":"a9b0e432-07db-42ce-9f3b-3f51888f80dd","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":null,"title":"The robust analysis is formalized in the following lemma","work_id":"deceb9f2-d543-441c-8fcf-e4ef1b35af31","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":null,"title":"Therefore, tr     X ι∈{0,1}2 LTι B′ 0B′ 1 ⊗ |ι⟩ ⟨ι|B′′ 0 B′′ 1   Γ(ψ)   ≥ 2 3 tr (|01⟩ ⟨01|+|10⟩ ⟨10|)B′′ 0 B′′ 1 Γ(ψ) (D23) S16 Combining the above two equations gives tr (|01⟩ ⟨01|+|10⟩ ⟨10|","work_id":"3012dcdf-426e-4938-a78b-eb6b30e9ea8b","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":null,"title":"The definition of the functionfis given in (D2)","work_id":"011af501-069e-4cad-963c-7c1ff474ad8e","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":null,"title":"This is because Γ l requires classical communication betweenA l andB l for the Pauli correction","work_id":"e5380b73-5637-4972-85bc-ce73c7af57f2","ref_index":5,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":36,"snapshot_sha256":"87c872da882b3e066bbdc840780075368b6a156659bd545bbeb4ebfaf01e71b8","internal_anchors":0},"formal_canon":{"evidence_count":2,"snapshot_sha256":"a9157df8cf1c88aefe703f1befc14ef479aa133017e1849829bb1e6bd54cf010"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}