{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2026:ATSDIYUXDPUQPCNMN53E5HAK6F","short_pith_number":"pith:ATSDIYUX","canonical_record":{"source":{"id":"2604.22650","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mes-hall","submitted_at":"2026-04-24T15:23:11Z","cross_cats_sorted":[],"title_canon_sha256":"42b39bdc52be28f6f52cc698ebd91f54fd2c98321614d59ba0d5a5def5da32ea","abstract_canon_sha256":"78a5d4aed801691d0744f03a3bb8203c22a9fe1e485564a88c21f41065880bc7"},"schema_version":"1.0"},"canonical_sha256":"04e43462971be90789ac6f764e9c0af17fa14c62a69ed27b955cdd3446e56651","source":{"kind":"arxiv","id":"2604.22650","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2604.22650","created_at":"2026-05-21T02:05:03Z"},{"alias_kind":"arxiv_version","alias_value":"2604.22650v2","created_at":"2026-05-21T02:05:03Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2604.22650","created_at":"2026-05-21T02:05:03Z"},{"alias_kind":"pith_short_12","alias_value":"ATSDIYUXDPUQ","created_at":"2026-05-21T02:05:03Z"},{"alias_kind":"pith_short_16","alias_value":"ATSDIYUXDPUQPCNM","created_at":"2026-05-21T02:05:03Z"},{"alias_kind":"pith_short_8","alias_value":"ATSDIYUX","created_at":"2026-05-21T02:05:03Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2026:ATSDIYUXDPUQPCNMN53E5HAK6F","target":"record","payload":{"canonical_record":{"source":{"id":"2604.22650","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mes-hall","submitted_at":"2026-04-24T15:23:11Z","cross_cats_sorted":[],"title_canon_sha256":"42b39bdc52be28f6f52cc698ebd91f54fd2c98321614d59ba0d5a5def5da32ea","abstract_canon_sha256":"78a5d4aed801691d0744f03a3bb8203c22a9fe1e485564a88c21f41065880bc7"},"schema_version":"1.0"},"canonical_sha256":"04e43462971be90789ac6f764e9c0af17fa14c62a69ed27b955cdd3446e56651","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-21T02:05:03.320428Z","signature_b64":"msinHOeA/goatH7XM68stptmz3qvO2dUCBGgvY6LTEaSz8tm1WovHvaK4pGIlwlg/w9cUMgpEEYVp1lS/j03Cg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"04e43462971be90789ac6f764e9c0af17fa14c62a69ed27b955cdd3446e56651","last_reissued_at":"2026-05-21T02:05:03.319726Z","signature_status":"signed_v1","first_computed_at":"2026-05-21T02:05:03.319726Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2604.22650","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-21T02:05:03Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ERnlSIsFbuohTWlJeDjXaEKIbdA1/Oz5ZLjfuU27KJRhQCBTo3KcC83Iz4mmhR20+LTCkQCYeGc/auSfWbi7DQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-21T12:05:17.682625Z"},"content_sha256":"32e67551ab66abd8a83f3fae6328065dcffdf45dfc0eebac627b270e742d1335","schema_version":"1.0","event_id":"sha256:32e67551ab66abd8a83f3fae6328065dcffdf45dfc0eebac627b270e742d1335"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2026:ATSDIYUXDPUQPCNMN53E5HAK6F","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Strain engineering of Andreev spin qubits in Germanium","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"Compressive strain suppresses spin splitting in germanium Josephson junctions, while unstrained and tensile-strained structures produce GHz-scale splittings and enable fast all-electric gates.","cross_cats":[],"primary_cat":"cond-mat.mes-hall","authors_text":"Anton Akhmerov, Antonio L. R. Manesco, Bernard van Heck, Patrick Del Vecchio, Stefano Bosco, Valla Fatemi, Vittorio Coppini","submitted_at":"2026-04-24T15:23:11Z","abstract_excerpt":"Planar germanium heterostructures are promising hosts for hybrid quantum devices due to their compatibility with superconductors, low material disorder, and relaxed fabrication constraints. Also, the potentially low density of nuclear spins and strong spin-orbit interaction make germanium attractive for coherent spin physics. However, recent microwave spectroscopy experiments were unable to resolve a spin-splitting of bound states in germanium Josephson junctions, the prerequisite for defining and controlling Andreev spin qubits. Here, we argue that compressive strain is the key mechanism supp"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"By numerically simulating ballistic Josephson junctions, we predict spin splittings comfortably in the GHz range, more than 2 orders of magnitude larger than compressively strained cases, and all-electric quantum gates in a hundred nanoseconds.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The numerical simulations of ballistic junctions accurately capture real-device physics, including the strain dependence of spin-orbit interaction without additional disorder or interface effects that could suppress the splitting.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Compressive strain suppresses spin splitting in germanium Josephson junctions while tensile or unstrained heterostructures enable GHz-scale splittings for Andreev spin qubits via enhanced spin-orbit effects.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Compressive strain suppresses spin splitting in germanium Josephson junctions, while unstrained and tensile-strained structures produce GHz-scale splittings and enable fast all-electric gates.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"26ed15d42f4d038e4d0a089a8e35c3189363f6da291f5c52d33a78ea482975c5"},"source":{"id":"2604.22650","kind":"arxiv","version":2},"verdict":{"id":"4cefbffd-8630-485e-a935-6fff226068f9","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-08T10:14:21.665685Z","strongest_claim":"By numerically simulating ballistic Josephson junctions, we predict spin splittings comfortably in the GHz range, more than 2 orders of magnitude larger than compressively strained cases, and all-electric quantum gates in a hundred nanoseconds.","one_line_summary":"Compressive strain suppresses spin splitting in germanium Josephson junctions while tensile or unstrained heterostructures enable GHz-scale splittings for Andreev spin qubits via enhanced spin-orbit effects.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The numerical simulations of ballistic junctions accurately capture real-device physics, including the strain dependence of spin-orbit interaction without additional disorder or interface effects that could suppress the splitting.","pith_extraction_headline":"Compressive strain suppresses spin splitting in germanium Josephson junctions, while unstrained and tensile-strained structures produce GHz-scale splittings and enable fast all-electric gates."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2604.22650/integrity.json","findings":[],"available":true,"detectors_run":[{"name":"doi_compliance","ran_at":"2026-05-19T23:46:33.291820Z","status":"completed","version":"1.0.0","findings_count":0}],"snapshot_sha256":"b44a4564ab053e0e66863f16a97319dc29ddcdf355377e81e0993f5bfa5bd4c6"},"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":"4cefbffd-8630-485e-a935-6fff226068f9"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-21T02:05:03Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"GvqtKFim4jHh3KfvJGUV8hv2F1KAm9wnuD3uSIQRD6DCJuwmXLLZw469A54J+oKUY3mq62GN0jq3luMY0JkFCg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-21T12:05:17.683366Z"},"content_sha256":"cba724b5bc7a09d17d93640ff1d7ad84d8c303466814b6ff9003fb2504d7f757","schema_version":"1.0","event_id":"sha256:cba724b5bc7a09d17d93640ff1d7ad84d8c303466814b6ff9003fb2504d7f757"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/ATSDIYUXDPUQPCNMN53E5HAK6F/bundle.json","state_url":"https://pith.science/pith/ATSDIYUXDPUQPCNMN53E5HAK6F/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/ATSDIYUXDPUQPCNMN53E5HAK6F/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":"2026-05-21T12:05:17Z","links":{"resolver":"https://pith.science/pith/ATSDIYUXDPUQPCNMN53E5HAK6F","bundle":"https://pith.science/pith/ATSDIYUXDPUQPCNMN53E5HAK6F/bundle.json","state":"https://pith.science/pith/ATSDIYUXDPUQPCNMN53E5HAK6F/state.json","well_known_bundle":"https://pith.science/.well-known/pith/ATSDIYUXDPUQPCNMN53E5HAK6F/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2026:ATSDIYUXDPUQPCNMN53E5HAK6F","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":"78a5d4aed801691d0744f03a3bb8203c22a9fe1e485564a88c21f41065880bc7","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mes-hall","submitted_at":"2026-04-24T15:23:11Z","title_canon_sha256":"42b39bdc52be28f6f52cc698ebd91f54fd2c98321614d59ba0d5a5def5da32ea"},"schema_version":"1.0","source":{"id":"2604.22650","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2604.22650","created_at":"2026-05-21T02:05:03Z"},{"alias_kind":"arxiv_version","alias_value":"2604.22650v2","created_at":"2026-05-21T02:05:03Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2604.22650","created_at":"2026-05-21T02:05:03Z"},{"alias_kind":"pith_short_12","alias_value":"ATSDIYUXDPUQ","created_at":"2026-05-21T02:05:03Z"},{"alias_kind":"pith_short_16","alias_value":"ATSDIYUXDPUQPCNM","created_at":"2026-05-21T02:05:03Z"},{"alias_kind":"pith_short_8","alias_value":"ATSDIYUX","created_at":"2026-05-21T02:05:03Z"}],"graph_snapshots":[{"event_id":"sha256:cba724b5bc7a09d17d93640ff1d7ad84d8c303466814b6ff9003fb2504d7f757","target":"graph","created_at":"2026-05-21T02:05:03Z","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":4,"items":[{"attestation":"unclaimed","claim_id":"C1","kind":"strongest_claim","source":"verdict.strongest_claim","status":"machine_extracted","text":"By numerically simulating ballistic Josephson junctions, we predict spin splittings comfortably in the GHz range, more than 2 orders of magnitude larger than compressively strained cases, and all-electric quantum gates in a hundred nanoseconds."},{"attestation":"unclaimed","claim_id":"C2","kind":"weakest_assumption","source":"verdict.weakest_assumption","status":"machine_extracted","text":"The numerical simulations of ballistic junctions accurately capture real-device physics, including the strain dependence of spin-orbit interaction without additional disorder or interface effects that could suppress the splitting."},{"attestation":"unclaimed","claim_id":"C3","kind":"one_line_summary","source":"verdict.one_line_summary","status":"machine_extracted","text":"Compressive strain suppresses spin splitting in germanium Josephson junctions while tensile or unstrained heterostructures enable GHz-scale splittings for Andreev spin qubits via enhanced spin-orbit effects."},{"attestation":"unclaimed","claim_id":"C4","kind":"headline","source":"verdict.pith_extraction.headline","status":"machine_extracted","text":"Compressive strain suppresses spin splitting in germanium Josephson junctions, while unstrained and tensile-strained structures produce GHz-scale splittings and enable fast all-electric gates."}],"snapshot_sha256":"26ed15d42f4d038e4d0a089a8e35c3189363f6da291f5c52d33a78ea482975c5"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"integrity":{"available":true,"clean":true,"detectors_run":[{"findings_count":0,"name":"doi_compliance","ran_at":"2026-05-19T23:46:33.291820Z","status":"completed","version":"1.0.0"}],"endpoint":"/pith/2604.22650/integrity.json","findings":[],"snapshot_sha256":"b44a4564ab053e0e66863f16a97319dc29ddcdf355377e81e0993f5bfa5bd4c6","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Planar germanium heterostructures are promising hosts for hybrid quantum devices due to their compatibility with superconductors, low material disorder, and relaxed fabrication constraints. Also, the potentially low density of nuclear spins and strong spin-orbit interaction make germanium attractive for coherent spin physics. However, recent microwave spectroscopy experiments were unable to resolve a spin-splitting of bound states in germanium Josephson junctions, the prerequisite for defining and controlling Andreev spin qubits. Here, we argue that compressive strain is the key mechanism supp","authors_text":"Anton Akhmerov, Antonio L. R. Manesco, Bernard van Heck, Patrick Del Vecchio, Stefano Bosco, Valla Fatemi, Vittorio Coppini","cross_cats":[],"headline":"Compressive strain suppresses spin splitting in germanium Josephson junctions, while unstrained and tensile-strained structures produce GHz-scale splittings and enable fast all-electric gates.","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mes-hall","submitted_at":"2026-04-24T15:23:11Z","title":"Strain engineering of Andreev spin qubits in Germanium"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2604.22650","kind":"arxiv","version":2},"verdict":{"created_at":"2026-05-08T10:14:21.665685Z","id":"4cefbffd-8630-485e-a935-6fff226068f9","model_set":{"reader":"grok-4.3"},"one_line_summary":"Compressive strain suppresses spin splitting in germanium Josephson junctions while tensile or unstrained heterostructures enable GHz-scale splittings for Andreev spin qubits via enhanced spin-orbit effects.","pipeline_version":"pith-pipeline@v0.9.0","pith_extraction_headline":"Compressive strain suppresses spin splitting in germanium Josephson junctions, while unstrained and tensile-strained structures produce GHz-scale splittings and enable fast all-electric gates.","strongest_claim":"By numerically simulating ballistic Josephson junctions, we predict spin splittings comfortably in the GHz range, more than 2 orders of magnitude larger than compressively strained cases, and all-electric quantum gates in a hundred nanoseconds.","weakest_assumption":"The numerical simulations of ballistic junctions accurately capture real-device physics, including the strain dependence of spin-orbit interaction without additional disorder or interface effects that could suppress the splitting."}},"verdict_id":"4cefbffd-8630-485e-a935-6fff226068f9"}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:32e67551ab66abd8a83f3fae6328065dcffdf45dfc0eebac627b270e742d1335","target":"record","created_at":"2026-05-21T02:05:03Z","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":"78a5d4aed801691d0744f03a3bb8203c22a9fe1e485564a88c21f41065880bc7","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mes-hall","submitted_at":"2026-04-24T15:23:11Z","title_canon_sha256":"42b39bdc52be28f6f52cc698ebd91f54fd2c98321614d59ba0d5a5def5da32ea"},"schema_version":"1.0","source":{"id":"2604.22650","kind":"arxiv","version":2}},"canonical_sha256":"04e43462971be90789ac6f764e9c0af17fa14c62a69ed27b955cdd3446e56651","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"04e43462971be90789ac6f764e9c0af17fa14c62a69ed27b955cdd3446e56651","first_computed_at":"2026-05-21T02:05:03.319726Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-21T02:05:03.319726Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"msinHOeA/goatH7XM68stptmz3qvO2dUCBGgvY6LTEaSz8tm1WovHvaK4pGIlwlg/w9cUMgpEEYVp1lS/j03Cg==","signature_status":"signed_v1","signed_at":"2026-05-21T02:05:03.320428Z","signed_message":"canonical_sha256_bytes"},"source_id":"2604.22650","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:32e67551ab66abd8a83f3fae6328065dcffdf45dfc0eebac627b270e742d1335","sha256:cba724b5bc7a09d17d93640ff1d7ad84d8c303466814b6ff9003fb2504d7f757"],"state_sha256":"f0fa0101bd2421ce9dc606e018d0f2fb89f14965411bb7ab941cc721eb5556c4"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"S1kHrf96gVscW1rtw1+LGOhH/WZqXWkwFmiR40HBqfUXer8hrBTVNl5EQscgh0zhHZZhFmKf7xgtJ0nDmV3vCw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-21T12:05:17.686029Z","bundle_sha256":"72100bbbb09551c972a19b02e6767aa1c045f1ae03170b6cebb80d7f43028b5a"}}