{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2009:OFCYXV6BNKX4BBVZVTRW62XE5T","short_pith_number":"pith:OFCYXV6B","canonical_record":{"source":{"id":"0901.4780","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mes-hall","submitted_at":"2009-01-29T21:04:41Z","cross_cats_sorted":[],"title_canon_sha256":"53dd2f68f909d6ddc6fed18a4f326a352ce8e893bb7920494d2e9fea44e628fb","abstract_canon_sha256":"00646ba62b37acad01ea3589278becc962ebcc986165efabd6c85c53e72735f8"},"schema_version":"1.0"},"canonical_sha256":"71458bd7c16aafc086b9ace36f6ae4ecf3af0dfa5b7833609d5bb2f42dc64f1d","source":{"kind":"arxiv","id":"0901.4780","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0901.4780","created_at":"2026-05-18T02:14:55Z"},{"alias_kind":"arxiv_version","alias_value":"0901.4780v2","created_at":"2026-05-18T02:14:55Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0901.4780","created_at":"2026-05-18T02:14:55Z"},{"alias_kind":"pith_short_12","alias_value":"OFCYXV6BNKX4","created_at":"2026-05-18T12:26:01Z"},{"alias_kind":"pith_short_16","alias_value":"OFCYXV6BNKX4BBVZ","created_at":"2026-05-18T12:26:01Z"},{"alias_kind":"pith_short_8","alias_value":"OFCYXV6B","created_at":"2026-05-18T12:26:01Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2009:OFCYXV6BNKX4BBVZVTRW62XE5T","target":"record","payload":{"canonical_record":{"source":{"id":"0901.4780","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mes-hall","submitted_at":"2009-01-29T21:04:41Z","cross_cats_sorted":[],"title_canon_sha256":"53dd2f68f909d6ddc6fed18a4f326a352ce8e893bb7920494d2e9fea44e628fb","abstract_canon_sha256":"00646ba62b37acad01ea3589278becc962ebcc986165efabd6c85c53e72735f8"},"schema_version":"1.0"},"canonical_sha256":"71458bd7c16aafc086b9ace36f6ae4ecf3af0dfa5b7833609d5bb2f42dc64f1d","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:14:55.080548Z","signature_b64":"PwnAiB7e+sOcfFjDbtd6z2x9ZgMARqi89FUyS3dleqCiQ7GFw7Q5VxChqg9nJ1HPufCthtImI3+jo9Ut4ll7Bw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"71458bd7c16aafc086b9ace36f6ae4ecf3af0dfa5b7833609d5bb2f42dc64f1d","last_reissued_at":"2026-05-18T02:14:55.079790Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:14:55.079790Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"0901.4780","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":"2026-05-18T02:14:55Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"g4XQ5U68rc8jOOgZzNcNx3w5IIbdhNTTnG3CHo2rjut+AWlmZJfu3em1mPL9Ro4DH8E8W4EfOq+Wdz2IxQeTCQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-09T01:20:04.623262Z"},"content_sha256":"905c7d1b59d93ca00ffc65afda4bcc5764e5ba9b14017263042a14a19b2c2b30","schema_version":"1.0","event_id":"sha256:905c7d1b59d93ca00ffc65afda4bcc5764e5ba9b14017263042a14a19b2c2b30"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2009:OFCYXV6BNKX4BBVZVTRW62XE5T","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Tunable Band Gap in Graphene with a Non-Centrosymmetric Superlattice Potential","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.mes-hall","authors_text":"D. Stroud, Rakesh P Tiwari","submitted_at":"2009-01-29T21:04:41Z","abstract_excerpt":"We show that, if graphene is subjected to the potential from an external superlattice, a band gap develops at the Dirac point provided the superlattice potential has broken inversion symmetry. As a numerical example, we calculate the band structure of graphene in the presence of an external potential due to periodically patterned gates arranged in a triangular graphene superlattice (TGS) with broken inversion symmetry, and find that a band gap is created at both the original and \"second generation\" Dirac point. The gap can be controlled, in principle, by changing the external potential and the"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0901.4780","kind":"arxiv","version":2},"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":"2026-05-18T02:14:55Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"rc6j6af4JR18Uc1VQ2NA9m8bWG4eUia3TlJaAqmt0MhvLZJbzcJGkJf9t2Mrq5RI73sFkWl67GZ1TkuUXX9WDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-09T01:20:04.623995Z"},"content_sha256":"53e4b45e7f1b3216f782e4357dcbabf4112ac111cda808644b55d46e5edd4441","schema_version":"1.0","event_id":"sha256:53e4b45e7f1b3216f782e4357dcbabf4112ac111cda808644b55d46e5edd4441"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/OFCYXV6BNKX4BBVZVTRW62XE5T/bundle.json","state_url":"https://pith.science/pith/OFCYXV6BNKX4BBVZVTRW62XE5T/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/OFCYXV6BNKX4BBVZVTRW62XE5T/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":"2026-06-09T01:20:04Z","links":{"resolver":"https://pith.science/pith/OFCYXV6BNKX4BBVZVTRW62XE5T","bundle":"https://pith.science/pith/OFCYXV6BNKX4BBVZVTRW62XE5T/bundle.json","state":"https://pith.science/pith/OFCYXV6BNKX4BBVZVTRW62XE5T/state.json","well_known_bundle":"https://pith.science/.well-known/pith/OFCYXV6BNKX4BBVZVTRW62XE5T/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2009:OFCYXV6BNKX4BBVZVTRW62XE5T","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":"00646ba62b37acad01ea3589278becc962ebcc986165efabd6c85c53e72735f8","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mes-hall","submitted_at":"2009-01-29T21:04:41Z","title_canon_sha256":"53dd2f68f909d6ddc6fed18a4f326a352ce8e893bb7920494d2e9fea44e628fb"},"schema_version":"1.0","source":{"id":"0901.4780","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0901.4780","created_at":"2026-05-18T02:14:55Z"},{"alias_kind":"arxiv_version","alias_value":"0901.4780v2","created_at":"2026-05-18T02:14:55Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0901.4780","created_at":"2026-05-18T02:14:55Z"},{"alias_kind":"pith_short_12","alias_value":"OFCYXV6BNKX4","created_at":"2026-05-18T12:26:01Z"},{"alias_kind":"pith_short_16","alias_value":"OFCYXV6BNKX4BBVZ","created_at":"2026-05-18T12:26:01Z"},{"alias_kind":"pith_short_8","alias_value":"OFCYXV6B","created_at":"2026-05-18T12:26:01Z"}],"graph_snapshots":[{"event_id":"sha256:53e4b45e7f1b3216f782e4357dcbabf4112ac111cda808644b55d46e5edd4441","target":"graph","created_at":"2026-05-18T02:14:55Z","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":"We show that, if graphene is subjected to the potential from an external superlattice, a band gap develops at the Dirac point provided the superlattice potential has broken inversion symmetry. As a numerical example, we calculate the band structure of graphene in the presence of an external potential due to periodically patterned gates arranged in a triangular graphene superlattice (TGS) with broken inversion symmetry, and find that a band gap is created at both the original and \"second generation\" Dirac point. The gap can be controlled, in principle, by changing the external potential and the","authors_text":"D. Stroud, Rakesh P Tiwari","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mes-hall","submitted_at":"2009-01-29T21:04:41Z","title":"Tunable Band Gap in Graphene with a Non-Centrosymmetric Superlattice Potential"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0901.4780","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":"sha256:905c7d1b59d93ca00ffc65afda4bcc5764e5ba9b14017263042a14a19b2c2b30","target":"record","created_at":"2026-05-18T02:14:55Z","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":"00646ba62b37acad01ea3589278becc962ebcc986165efabd6c85c53e72735f8","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mes-hall","submitted_at":"2009-01-29T21:04:41Z","title_canon_sha256":"53dd2f68f909d6ddc6fed18a4f326a352ce8e893bb7920494d2e9fea44e628fb"},"schema_version":"1.0","source":{"id":"0901.4780","kind":"arxiv","version":2}},"canonical_sha256":"71458bd7c16aafc086b9ace36f6ae4ecf3af0dfa5b7833609d5bb2f42dc64f1d","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"71458bd7c16aafc086b9ace36f6ae4ecf3af0dfa5b7833609d5bb2f42dc64f1d","first_computed_at":"2026-05-18T02:14:55.079790Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:14:55.079790Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"PwnAiB7e+sOcfFjDbtd6z2x9ZgMARqi89FUyS3dleqCiQ7GFw7Q5VxChqg9nJ1HPufCthtImI3+jo9Ut4ll7Bw==","signature_status":"signed_v1","signed_at":"2026-05-18T02:14:55.080548Z","signed_message":"canonical_sha256_bytes"},"source_id":"0901.4780","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:905c7d1b59d93ca00ffc65afda4bcc5764e5ba9b14017263042a14a19b2c2b30","sha256:53e4b45e7f1b3216f782e4357dcbabf4112ac111cda808644b55d46e5edd4441"],"state_sha256":"c4e4ec36899470705ea6ab21a2020fd71eec4888058a87a92e7448fbc7f0c2c2"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"rZQGLNF1IMqBrB7hJYOuVpN1Kxavf9CTJmmpvc8OwnudGr8ZIoyFf07jAreWrsVWqmdLf54e21B+AUuGpeD7Cw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-09T01:20:04.627859Z","bundle_sha256":"02ab98030d581a555630bd53cbf24f49d742829270855ea10fa354fec2cd720f"}}