{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2022:EKA6YJCXL7SJAGF7IIQDAKRS2L","short_pith_number":"pith:EKA6YJCX","canonical_record":{"source":{"id":"2207.02708","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"quant-ph","submitted_at":"2022-07-06T14:29:11Z","cross_cats_sorted":[],"title_canon_sha256":"1ca4886de453773cb228bc9ae7a6ede9f4f3f7be584bedfad4525d6dc8c68b20","abstract_canon_sha256":"2a732e90305bd77d6260b10867c45cdc3804cf7335349905d4bbe1f9c7706093"},"schema_version":"1.0"},"canonical_sha256":"2281ec24575fe49018bf4220302a32d2c3c9e2a6ee11416a8c2c1d2e48c6d0a9","source":{"kind":"arxiv","id":"2207.02708","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2207.02708","created_at":"2026-07-05T07:00:19Z"},{"alias_kind":"arxiv_version","alias_value":"2207.02708v1","created_at":"2026-07-05T07:00:19Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2207.02708","created_at":"2026-07-05T07:00:19Z"},{"alias_kind":"pith_short_12","alias_value":"EKA6YJCXL7SJ","created_at":"2026-07-05T07:00:19Z"},{"alias_kind":"pith_short_16","alias_value":"EKA6YJCXL7SJAGF7","created_at":"2026-07-05T07:00:19Z"},{"alias_kind":"pith_short_8","alias_value":"EKA6YJCX","created_at":"2026-07-05T07:00:19Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2022:EKA6YJCXL7SJAGF7IIQDAKRS2L","target":"record","payload":{"canonical_record":{"source":{"id":"2207.02708","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"quant-ph","submitted_at":"2022-07-06T14:29:11Z","cross_cats_sorted":[],"title_canon_sha256":"1ca4886de453773cb228bc9ae7a6ede9f4f3f7be584bedfad4525d6dc8c68b20","abstract_canon_sha256":"2a732e90305bd77d6260b10867c45cdc3804cf7335349905d4bbe1f9c7706093"},"schema_version":"1.0"},"canonical_sha256":"2281ec24575fe49018bf4220302a32d2c3c9e2a6ee11416a8c2c1d2e48c6d0a9","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T07:00:19.115639Z","signature_b64":"QHKUd04y192jpxkTVtOGBdTNXDImCNmpCxlDhG0gBoLXbGOh5zH8o6EHzyBGlrLIiCUuhCtTLSRmNkOZiIszAg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"2281ec24575fe49018bf4220302a32d2c3c9e2a6ee11416a8c2c1d2e48c6d0a9","last_reissued_at":"2026-07-05T07:00:19.115163Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T07:00:19.115163Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2207.02708","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T07:00:19Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"j6yX/SMRGd3TNDN3W9Umtimexn4DqshF7hhW+/hPChGqKzrjiQFdQMZCsotCk+66T1KrMC+mHSwx2tz40TDJCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-20T11:44:09.944627Z"},"content_sha256":"25debff056c6c4d4677216762656f091d84992dfae8ef2bb9066872d7a863ae2","schema_version":"1.0","event_id":"sha256:25debff056c6c4d4677216762656f091d84992dfae8ef2bb9066872d7a863ae2"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2022:EKA6YJCXL7SJAGF7IIQDAKRS2L","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Robust millisecond coherence times of erbium electron spins","license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","headline":"","cross_cats":[],"primary_cat":"quant-ph","authors_text":"Haitao Zhang, Jun Yang, Shobhit Gupta, Tian Zhong, Xuntao Wu","submitted_at":"2022-07-06T14:29:11Z","abstract_excerpt":"Erbium-doped solids are prime candidates for optical quantum communication networks due to erbium's telecom C-band emission. A long-lived electron spin of erbium with millisecond coherence time is highly desirable for establishing entanglement between adjacent quantum repeater nodes while long-term storage of the entanglement could rely on transferring to erbium's second-long coherence nuclear spins. Here we report GHz-range electron spin transitions of $^{167}\\mathrm{Er}^{3+}$ in yttrium oxide ($\\mathrm{Y_2O_3}$) matrix with coherence times that are consistently longer than a millisecond. Ins"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2207.02708","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2207.02708/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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":"2026-07-05T07:00:19Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"KBcDgt+UOrejaB+7FX4DypMX+H0zQ0f8DmOVvyegFgKF4O2yl93/bHnYo6tOFDScELUByP9Flshgpq7HTZWJCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-20T11:44:09.945885Z"},"content_sha256":"637eaa12c2d3a7fd9398257b0600baf0637ade83eb50aa8692e04e7ab5bc4b28","schema_version":"1.0","event_id":"sha256:637eaa12c2d3a7fd9398257b0600baf0637ade83eb50aa8692e04e7ab5bc4b28"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/EKA6YJCXL7SJAGF7IIQDAKRS2L/bundle.json","state_url":"https://pith.science/pith/EKA6YJCXL7SJAGF7IIQDAKRS2L/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/EKA6YJCXL7SJAGF7IIQDAKRS2L/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":"2026-08-20T11:44:09Z","links":{"resolver":"https://pith.science/pith/EKA6YJCXL7SJAGF7IIQDAKRS2L","bundle":"https://pith.science/pith/EKA6YJCXL7SJAGF7IIQDAKRS2L/bundle.json","state":"https://pith.science/pith/EKA6YJCXL7SJAGF7IIQDAKRS2L/state.json","well_known_bundle":"https://pith.science/.well-known/pith/EKA6YJCXL7SJAGF7IIQDAKRS2L/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2022:EKA6YJCXL7SJAGF7IIQDAKRS2L","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":"2a732e90305bd77d6260b10867c45cdc3804cf7335349905d4bbe1f9c7706093","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"quant-ph","submitted_at":"2022-07-06T14:29:11Z","title_canon_sha256":"1ca4886de453773cb228bc9ae7a6ede9f4f3f7be584bedfad4525d6dc8c68b20"},"schema_version":"1.0","source":{"id":"2207.02708","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2207.02708","created_at":"2026-07-05T07:00:19Z"},{"alias_kind":"arxiv_version","alias_value":"2207.02708v1","created_at":"2026-07-05T07:00:19Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2207.02708","created_at":"2026-07-05T07:00:19Z"},{"alias_kind":"pith_short_12","alias_value":"EKA6YJCXL7SJ","created_at":"2026-07-05T07:00:19Z"},{"alias_kind":"pith_short_16","alias_value":"EKA6YJCXL7SJAGF7","created_at":"2026-07-05T07:00:19Z"},{"alias_kind":"pith_short_8","alias_value":"EKA6YJCX","created_at":"2026-07-05T07:00:19Z"}],"graph_snapshots":[{"event_id":"sha256:637eaa12c2d3a7fd9398257b0600baf0637ade83eb50aa8692e04e7ab5bc4b28","target":"graph","created_at":"2026-07-05T07:00:19Z","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"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2207.02708/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Erbium-doped solids are prime candidates for optical quantum communication networks due to erbium's telecom C-band emission. A long-lived electron spin of erbium with millisecond coherence time is highly desirable for establishing entanglement between adjacent quantum repeater nodes while long-term storage of the entanglement could rely on transferring to erbium's second-long coherence nuclear spins. Here we report GHz-range electron spin transitions of $^{167}\\mathrm{Er}^{3+}$ in yttrium oxide ($\\mathrm{Y_2O_3}$) matrix with coherence times that are consistently longer than a millisecond. Ins","authors_text":"Haitao Zhang, Jun Yang, Shobhit Gupta, Tian Zhong, Xuntao Wu","cross_cats":[],"headline":"","license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"quant-ph","submitted_at":"2022-07-06T14:29:11Z","title":"Robust millisecond coherence times of erbium electron spins"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2207.02708","kind":"arxiv","version":1},"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":"sha256:25debff056c6c4d4677216762656f091d84992dfae8ef2bb9066872d7a863ae2","target":"record","created_at":"2026-07-05T07:00:19Z","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":"2a732e90305bd77d6260b10867c45cdc3804cf7335349905d4bbe1f9c7706093","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"quant-ph","submitted_at":"2022-07-06T14:29:11Z","title_canon_sha256":"1ca4886de453773cb228bc9ae7a6ede9f4f3f7be584bedfad4525d6dc8c68b20"},"schema_version":"1.0","source":{"id":"2207.02708","kind":"arxiv","version":1}},"canonical_sha256":"2281ec24575fe49018bf4220302a32d2c3c9e2a6ee11416a8c2c1d2e48c6d0a9","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"2281ec24575fe49018bf4220302a32d2c3c9e2a6ee11416a8c2c1d2e48c6d0a9","first_computed_at":"2026-07-05T07:00:19.115163Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T07:00:19.115163Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"QHKUd04y192jpxkTVtOGBdTNXDImCNmpCxlDhG0gBoLXbGOh5zH8o6EHzyBGlrLIiCUuhCtTLSRmNkOZiIszAg==","signature_status":"signed_v1","signed_at":"2026-07-05T07:00:19.115639Z","signed_message":"canonical_sha256_bytes"},"source_id":"2207.02708","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:25debff056c6c4d4677216762656f091d84992dfae8ef2bb9066872d7a863ae2","sha256:637eaa12c2d3a7fd9398257b0600baf0637ade83eb50aa8692e04e7ab5bc4b28"],"state_sha256":"20ad3d7a346be644f51e0894166622ae3a3b75727822ab5178b9b10ef9844f81"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"PR2aJI8h7VrDMK7or3Iog3Rq8ftosZUL1A2tQQp0k8HB6Q0hj9yDbcAblsa3cU1+Gu56jT2HSOoR4hCiT1SNBw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-20T11:44:09.960126Z","bundle_sha256":"1020b81e89a3f0bfa3ef8ca604a88ace92365dc886916397016f3d2676dfe232"}}