{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:1999:XMG2BFQKRSVIVPXS62AAZFNWBY","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":"979fe3442ab2858d4eb6860fcb61b587c4b64898ea02e6cbfe73e178e3568569","cross_cats_sorted":[],"license":"","primary_cat":"cond-mat.mes-hall","submitted_at":"1999-09-20T15:09:30Z","title_canon_sha256":"4af3dafb3570f4d6d81bfbb1c348bf864e26ba23d34dc9b724fe91ea1fefa3bc"},"schema_version":"1.0","source":{"id":"cond-mat/9909293","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"cond-mat/9909293","created_at":"2026-05-18T03:28:54Z"},{"alias_kind":"arxiv_version","alias_value":"cond-mat/9909293v2","created_at":"2026-05-18T03:28:54Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.cond-mat/9909293","created_at":"2026-05-18T03:28:54Z"},{"alias_kind":"pith_short_12","alias_value":"XMG2BFQKRSVI","created_at":"2026-05-18T12:25:49Z"},{"alias_kind":"pith_short_16","alias_value":"XMG2BFQKRSVIVPXS","created_at":"2026-05-18T12:25:49Z"},{"alias_kind":"pith_short_8","alias_value":"XMG2BFQK","created_at":"2026-05-18T12:25:49Z"}],"graph_snapshots":[{"event_id":"sha256:75899e6e5c44ceec5e674703c9897c827bcb65d92af1d0014a62a8d5f5b6e590","target":"graph","created_at":"2026-05-18T03:28:54Z","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":"This is a tutorial article based on a lecture delivered in June 1999 at the NATO Advanced Study Institute in Ankara. The phenomenon of Andreev reflection is introduced as the electronic analogue of optical phase-conjugation. In the optical problem, a disordered medium backed by a phase-conjugating mirror can become completely transparent. Yet, a disordered metal connected to a superconductor has the same resistance as in the normal state. The resolution of this paradox teaches us a fundamental difference between phase conjugation of light and electrons.","authors_text":"C.W.J. Beenakker","cross_cats":[],"headline":"","license":"","primary_cat":"cond-mat.mes-hall","submitted_at":"1999-09-20T15:09:30Z","title":"Why does a metal-superconductor junction have a resistance?"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"cond-mat/9909293","kind":"arxiv","version":2},"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":"sha256:9aec600a5ad129e1e829fbdcad03c548ef7b9a02ca2dc0c21e5b55ab16f9a271","target":"record","created_at":"2026-05-18T03:28:54Z","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":"979fe3442ab2858d4eb6860fcb61b587c4b64898ea02e6cbfe73e178e3568569","cross_cats_sorted":[],"license":"","primary_cat":"cond-mat.mes-hall","submitted_at":"1999-09-20T15:09:30Z","title_canon_sha256":"4af3dafb3570f4d6d81bfbb1c348bf864e26ba23d34dc9b724fe91ea1fefa3bc"},"schema_version":"1.0","source":{"id":"cond-mat/9909293","kind":"arxiv","version":2}},"canonical_sha256":"bb0da0960a8caa8abef2f6800c95b60e322faa918dbfcfa1356ac66c772cdd1f","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"bb0da0960a8caa8abef2f6800c95b60e322faa918dbfcfa1356ac66c772cdd1f","first_computed_at":"2026-05-18T03:28:54.579402Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T03:28:54.579402Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"OKjhaUZBGD3ilheJKnw7iPd8On7tZyDDDeXFwibB3QlWXKiKmeUh0ga8lI7laVvLEp1A2Zzqh9CVb85C53HpDA==","signature_status":"signed_v1","signed_at":"2026-05-18T03:28:54.579916Z","signed_message":"canonical_sha256_bytes"},"source_id":"cond-mat/9909293","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:9aec600a5ad129e1e829fbdcad03c548ef7b9a02ca2dc0c21e5b55ab16f9a271","sha256:75899e6e5c44ceec5e674703c9897c827bcb65d92af1d0014a62a8d5f5b6e590"],"state_sha256":"c65972fcec525bf2d0c9e0d6be70c261ecfaed83f6ff7bf6ede23cb97d7be363"}