{"paper":{"title":"Quantum simulation of nanographenes and Trotter error cancellation","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"Trotter error cancels for energy differences in nanographene simulations, cutting circuit depth by an order of magnitude.","cross_cats":[],"primary_cat":"quant-ph","authors_text":"Andreas Juul Bay-Smidt, Earl T. Campbell, Gemma C. Solomon, Marcel D. Fabian, Nick S. Blunt, Nina Glaser","submitted_at":"2026-05-01T15:49:52Z","abstract_excerpt":"Fault-tolerant quantum computing is a promising tool for simulating molecules and materials, but frequently-considered applications require substantial resources, and the gap between hardware capabilities and requirements remains significant. We propose quantum simulation of nanographene $\\pi$-systems as relevant and scalable problems to span the gap between early and large-scale fault-tolerant quantum computing. We examine the efficiency of Trotterized quantum simulation, present a detailed analysis of worst-case, average-case and energy eigenvalue Trotter errors, and show that these Trotter "},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"We observe a Trotter error cancellation phenomenon whereby the Trotter error for energy differences between low-lying eigenstates is significantly smaller than the Trotter error for absolute energies, resulting in approximately an order of magnitude circuit depth reduction for quantum phase estimation calculation of energy gaps.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The tensor-network-based approach correctly estimates Trotter eigenvalue errors for systems beyond brute-force calculation, as used to obtain the spectral analysis and resource estimates for nanographenes up to 140 spin orbitals.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Trotter error cancellation in nanographene simulations reduces circuit depth by about 10x for quantum phase estimation of energy gaps to chemical accuracy in the Pariser-Parr-Pople model.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Trotter error cancels for energy differences in nanographene simulations, cutting circuit depth by an order of magnitude.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"8991d69b6b2fdbf8f09858499c3a134013f4e67bac2cb656f86fb65c0b898e28"},"source":{"id":"2605.00745","kind":"arxiv","version":2},"verdict":{"id":"69c55bf8-d565-4f3d-9f3f-ee8a892f2cde","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-19T18:08:16.780540Z","strongest_claim":"We observe a Trotter error cancellation phenomenon whereby the Trotter error for energy differences between low-lying eigenstates is significantly smaller than the Trotter error for absolute energies, resulting in approximately an order of magnitude circuit depth reduction for quantum phase estimation calculation of energy gaps.","one_line_summary":"Trotter error cancellation in nanographene simulations reduces circuit depth by about 10x for quantum phase estimation of energy gaps to chemical accuracy in the Pariser-Parr-Pople model.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The tensor-network-based approach correctly estimates Trotter eigenvalue errors for systems beyond brute-force calculation, as used to obtain the spectral analysis and resource estimates for nanographenes up to 140 spin orbitals.","pith_extraction_headline":"Trotter error cancels for energy differences in nanographene simulations, cutting circuit depth by an order of magnitude."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2605.00745/integrity.json","findings":[],"available":true,"detectors_run":[{"name":"doi_compliance","ran_at":"2026-05-19T17:53:02.392112Z","status":"completed","version":"1.0.0","findings_count":0}],"snapshot_sha256":"98bddb6e546862cab420896b586de646cebe353348d162cc665547ef4111f9ce"},"references":{"count":105,"sample":[{"doi":"","year":1964,"title":"P. Hohenberg and W. Kohn, Inhomogeneous electron gas, Phys. Rev.136, B864 (1964)","work_id":"e7444271-6d6a-48d8-9252-1e14152bf10c","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":1965,"title":"W. Kohn and L. J. Sham, Self-consistent equations in- cluding exchange and correlation effects, Phys. Rev.140, A1133 (1965)","work_id":"a644b954-eb11-4834-821a-88a0c0567165","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2008,"title":"A. J. Cohen, P. Mori-S´ anchez, and W. Yang, Insights into current limitations of density functional theory, Science 321, 792 (2008)","work_id":"36645601-2751-4440-bcb0-ac01d13b331a","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2012,"title":"K. Burke, Perspective on density functional theory, J. Chem. Phys.136, 150901 (2012)","work_id":"4c852495-f5f5-4229-ba75-71790749fed8","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2017,"title":"N. Mardirossian and M. Head-Gordon, Thirty years of density functional theory in computational chemistry: an overview and extensive assessment of 200 density func- tionals, Mol. Phys.115, 2315 (2017)","work_id":"7a4865cf-9eb4-4364-a814-a8661b58e9cc","ref_index":5,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":105,"snapshot_sha256":"f1894d09a8834eebc3d5f44b5dec0c0486672a6789fc5c38c6393ae6ff50c328","internal_anchors":2},"formal_canon":{"evidence_count":2,"snapshot_sha256":"7f653fb7def6f7d80761ccddaa78ca35edb5c2f010a6a9d66a17f34f53ecff6b"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}