{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:GLWF4DLGJXDUE3APCF46FXQ3VC","short_pith_number":"pith:GLWF4DLG","canonical_record":{"source":{"id":"1811.02917","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2018-11-07T14:53:39Z","cross_cats_sorted":[],"title_canon_sha256":"89fc990fc993a0dafb950d92ee600abd15bd96262ddb5de52ddbe24059849066","abstract_canon_sha256":"1c240b5793f5b1ac2bcf461c3fed905433be15bf84c8901017261d7dc3a276d0"},"schema_version":"1.0"},"canonical_sha256":"32ec5e0d664dc7426c0f1179e2de1ba8860afc8dc2a995cc91176738dfa9ea66","source":{"kind":"arxiv","id":"1811.02917","version":3},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1811.02917","created_at":"2026-05-17T23:42:26Z"},{"alias_kind":"arxiv_version","alias_value":"1811.02917v3","created_at":"2026-05-17T23:42:26Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1811.02917","created_at":"2026-05-17T23:42:26Z"},{"alias_kind":"pith_short_12","alias_value":"GLWF4DLGJXDU","created_at":"2026-05-18T12:32:25Z"},{"alias_kind":"pith_short_16","alias_value":"GLWF4DLGJXDUE3AP","created_at":"2026-05-18T12:32:25Z"},{"alias_kind":"pith_short_8","alias_value":"GLWF4DLG","created_at":"2026-05-18T12:32:25Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:GLWF4DLGJXDUE3APCF46FXQ3VC","target":"record","payload":{"canonical_record":{"source":{"id":"1811.02917","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2018-11-07T14:53:39Z","cross_cats_sorted":[],"title_canon_sha256":"89fc990fc993a0dafb950d92ee600abd15bd96262ddb5de52ddbe24059849066","abstract_canon_sha256":"1c240b5793f5b1ac2bcf461c3fed905433be15bf84c8901017261d7dc3a276d0"},"schema_version":"1.0"},"canonical_sha256":"32ec5e0d664dc7426c0f1179e2de1ba8860afc8dc2a995cc91176738dfa9ea66","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:42:26.599453Z","signature_b64":"w85sjxWgK6opFPqkyY6BDSGQ8gy5uRMz+tdNx8fGfvAfaWidnrbpEmZalgSP8euplkNrQQ8E9xG5Uh8gSZW+CQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"32ec5e0d664dc7426c0f1179e2de1ba8860afc8dc2a995cc91176738dfa9ea66","last_reissued_at":"2026-05-17T23:42:26.598776Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:42:26.598776Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1811.02917","source_version":3,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-17T23:42:26Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"nsxOEz7hXR6qzbm0IbalwjQsnKv6OqLo2M0AcixbMef4NO7ORuaHvKsrsZ270SW2/XxZulbinrqA61t/puSVAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-18T18:35:08.041239Z"},"content_sha256":"66e43b58d99587b9e34226e6b85672c80728d483e533d9c6f86f138ea0d45532","schema_version":"1.0","event_id":"sha256:66e43b58d99587b9e34226e6b85672c80728d483e533d9c6f86f138ea0d45532"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:GLWF4DLGJXDUE3APCF46FXQ3VC","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Efficiency of a quantum Otto heat engine operating under a reservoir at effective negative temperatures","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"quant-ph","authors_text":"Alexandre M. de Souza, Celso J. Villas-Boas, Ivan S. Oliveira, Norton G. de Almeida, Roberto S. Sarthour, Rog\\'erio J. de Assis, Taysa M. de Mendon\\c{c}a","submitted_at":"2018-11-07T14:53:39Z","abstract_excerpt":"Abstract We perform an experiment in which a quantum heat engine works under two reservoirs, one at a positive spin temperature and the other at an effective negative spin temperature i.e., when the spin system presents population inversion. We show that the efficiency of this engine can be greater than that when both reservoirs are at positive temperatures. We also demonstrate the counter-intuitive result that the Otto efficiency can be beaten only when the quantum engine is operating in the finite-time mode."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1811.02917","kind":"arxiv","version":3},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"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"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-17T23:42:26Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"GSCRBcHjXo92eSvIYOgdV+zxw2SRSV/eOq0PNE9gQk0wSAmA9bBiJDxMmOcMrBEgFJsSsmbU0hBltf2+peQJBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-18T18:35:08.041898Z"},"content_sha256":"ad20d0a0875586aa33355348c43a5394a3bd06941ca9df0e1a93cdb60d70cce2","schema_version":"1.0","event_id":"sha256:ad20d0a0875586aa33355348c43a5394a3bd06941ca9df0e1a93cdb60d70cce2"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/GLWF4DLGJXDUE3APCF46FXQ3VC/bundle.json","state_url":"https://pith.science/pith/GLWF4DLGJXDUE3APCF46FXQ3VC/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/GLWF4DLGJXDUE3APCF46FXQ3VC/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-05-18T18:35:08Z","links":{"resolver":"https://pith.science/pith/GLWF4DLGJXDUE3APCF46FXQ3VC","bundle":"https://pith.science/pith/GLWF4DLGJXDUE3APCF46FXQ3VC/bundle.json","state":"https://pith.science/pith/GLWF4DLGJXDUE3APCF46FXQ3VC/state.json","well_known_bundle":"https://pith.science/.well-known/pith/GLWF4DLGJXDUE3APCF46FXQ3VC/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:GLWF4DLGJXDUE3APCF46FXQ3VC","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"1c240b5793f5b1ac2bcf461c3fed905433be15bf84c8901017261d7dc3a276d0","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2018-11-07T14:53:39Z","title_canon_sha256":"89fc990fc993a0dafb950d92ee600abd15bd96262ddb5de52ddbe24059849066"},"schema_version":"1.0","source":{"id":"1811.02917","kind":"arxiv","version":3}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1811.02917","created_at":"2026-05-17T23:42:26Z"},{"alias_kind":"arxiv_version","alias_value":"1811.02917v3","created_at":"2026-05-17T23:42:26Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1811.02917","created_at":"2026-05-17T23:42:26Z"},{"alias_kind":"pith_short_12","alias_value":"GLWF4DLGJXDU","created_at":"2026-05-18T12:32:25Z"},{"alias_kind":"pith_short_16","alias_value":"GLWF4DLGJXDUE3AP","created_at":"2026-05-18T12:32:25Z"},{"alias_kind":"pith_short_8","alias_value":"GLWF4DLG","created_at":"2026-05-18T12:32:25Z"}],"graph_snapshots":[{"event_id":"sha256:ad20d0a0875586aa33355348c43a5394a3bd06941ca9df0e1a93cdb60d70cce2","target":"graph","created_at":"2026-05-17T23:42:26Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"paper":{"abstract_excerpt":"Abstract We perform an experiment in which a quantum heat engine works under two reservoirs, one at a positive spin temperature and the other at an effective negative spin temperature i.e., when the spin system presents population inversion. We show that the efficiency of this engine can be greater than that when both reservoirs are at positive temperatures. We also demonstrate the counter-intuitive result that the Otto efficiency can be beaten only when the quantum engine is operating in the finite-time mode.","authors_text":"Alexandre M. de Souza, Celso J. Villas-Boas, Ivan S. Oliveira, Norton G. de Almeida, Roberto S. Sarthour, Rog\\'erio J. de Assis, Taysa M. de Mendon\\c{c}a","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2018-11-07T14:53:39Z","title":"Efficiency of a quantum Otto heat engine operating under a reservoir at effective negative temperatures"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1811.02917","kind":"arxiv","version":3},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:66e43b58d99587b9e34226e6b85672c80728d483e533d9c6f86f138ea0d45532","target":"record","created_at":"2026-05-17T23:42:26Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"1c240b5793f5b1ac2bcf461c3fed905433be15bf84c8901017261d7dc3a276d0","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2018-11-07T14:53:39Z","title_canon_sha256":"89fc990fc993a0dafb950d92ee600abd15bd96262ddb5de52ddbe24059849066"},"schema_version":"1.0","source":{"id":"1811.02917","kind":"arxiv","version":3}},"canonical_sha256":"32ec5e0d664dc7426c0f1179e2de1ba8860afc8dc2a995cc91176738dfa9ea66","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"32ec5e0d664dc7426c0f1179e2de1ba8860afc8dc2a995cc91176738dfa9ea66","first_computed_at":"2026-05-17T23:42:26.598776Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:42:26.598776Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"w85sjxWgK6opFPqkyY6BDSGQ8gy5uRMz+tdNx8fGfvAfaWidnrbpEmZalgSP8euplkNrQQ8E9xG5Uh8gSZW+CQ==","signature_status":"signed_v1","signed_at":"2026-05-17T23:42:26.599453Z","signed_message":"canonical_sha256_bytes"},"source_id":"1811.02917","source_kind":"arxiv","source_version":3}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:66e43b58d99587b9e34226e6b85672c80728d483e533d9c6f86f138ea0d45532","sha256:ad20d0a0875586aa33355348c43a5394a3bd06941ca9df0e1a93cdb60d70cce2"],"state_sha256":"d930187f643f5c526252d1e78a20fc161d25686066edfb5d475efdcd80a6180b"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"PNf+3Z36GgoRkqznt+AYwoKnU/ADbSMK+hZfXonR0DbRAV3BFREsH0BT2YXTEqSOrvJpOp28Y/q6Vuop7/5VAw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-18T18:35:08.043859Z","bundle_sha256":"32fd38927788c3b5770473272bf67164903300048177b62ba31739ec039ff758"}}