{"paper":{"title":"Nonequilibrium thermometry via an ensemble of initially correlated qubits","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"Initial quantum correlations among qubits enhance the Quantum Fisher Information for bath temperature estimation during nonequilibrium thermalization.","cross_cats":[],"primary_cat":"quant-ph","authors_text":"Enrico Trombetti, Marco Malitesta, Marco Pezzutto, Stefano Gherardini","submitted_at":"2025-07-04T10:49:39Z","abstract_excerpt":"We investigate a nonequilibrium quantum thermometry protocol in which an ensemble of qubits, acting as temperature probes, is weakly coupled to a macroscopic thermal bath. The temperature of the bath, the parameter of interest, is encoded in the dissipator of a Markovian thermalization process. For some relevant initial states, we observe a peak in the Quantum Fisher Information (QFI) during the transient of the thermalization, indicating enhanced sensitivity in early-time dynamics. This effect becomes more pronounced at higher bath temperatures and is further enhanced when the initial reduced"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"We find strong numerical evidence that, given same single-qubit reduced states, the inclusion of quantum correlations among the qubits of the ensemble always yields an enhanced QFI.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The qubits remain weakly coupled to a macroscopic thermal bath so that the reduced dynamics is accurately described by a Markovian master equation with a temperature-dependent dissipator (abstract and implied in the protocol description).","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Initial quantum correlations among qubits enhance quantum Fisher information for temperature estimation in nonequilibrium Markovian thermalization, with early-time peaks and near-standard-quantum-limit performance for entangled states at high temperatures.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Initial quantum correlations among qubits enhance the Quantum Fisher Information for bath temperature estimation during nonequilibrium thermalization.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"2e7394179a6fa075cafa73b444ae467c9cff9ffddb9be8b6327c6ad1228d1cdd"},"source":{"id":"2507.03471","kind":"arxiv","version":2},"verdict":{"id":"4805f912-5d76-439e-8c00-cf48500bc5e8","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-19T06:35:12.047113Z","strongest_claim":"We find strong numerical evidence that, given same single-qubit reduced states, the inclusion of quantum correlations among the qubits of the ensemble always yields an enhanced QFI.","one_line_summary":"Initial quantum correlations among qubits enhance quantum Fisher information for temperature estimation in nonequilibrium Markovian thermalization, with early-time peaks and near-standard-quantum-limit performance for entangled states at high temperatures.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The qubits remain weakly coupled to a macroscopic thermal bath so that the reduced dynamics is accurately described by a Markovian master equation with a temperature-dependent dissipator (abstract and implied in the protocol description).","pith_extraction_headline":"Initial quantum correlations among qubits enhance the Quantum Fisher Information for bath temperature estimation during nonequilibrium thermalization."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2507.03471/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":55,"sample":[{"doi":"","year":null,"title":"Time-evolution of a multi-qubit state The nonequilibrium thermometry setting, which we are referring to, considers a model where the interaction be- tween each qubit thermometer and the thermal bath i","work_id":"555a1f2e-ba01-49e2-8868-5f22b780e138","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2020,"title":"Quan- tum Reservoir Computing (QuReCo)","work_id":"ec6e44a8-5d3c-4194-8543-0f4ca09ac075","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":null,"title":"ˆK1 = 1 2 ∂β q 0 0 q(1 − p) , ∂β( ˆK †","work_id":"f2606627-f6ff-46cd-84b7-7030e78b2c61","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":null,"title":"ˆK2 = 1 2 ∂β 0 0 0 pq , ∂β( ˆK †","work_id":"84a8c1ae-1a1d-4d3a-b32a-226bb4ee35c4","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":null,"title":"ˆK3 = 1 2 ∂β (1 − p)(1 − q) 0 0 −q , ∂β( ˆK †","work_id":"eecf2dae-402b-4cf9-9b93-ef19c243de04","ref_index":5,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":55,"snapshot_sha256":"2c8e2875486bb651f0385fe68b580ae67b18ad5c2629b6aa762a91b5d30fdc81","internal_anchors":0},"formal_canon":{"evidence_count":2,"snapshot_sha256":"829f9602daf371d9681e3e9286bbd57006b52579ef45d3cb09b3d55cc8a24ea0"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}