{"paper":{"title":"Hidden time-nonlocal Floquet symmetries","license":"http://creativecommons.org/licenses/by/4.0/","headline":"A hidden time-nonlocal parity symmetry produces exact quasienergy crossings in driven two-level systems when detuning is an integer multiple of the drive quantum.","cross_cats":["cond-mat.mes-hall"],"primary_cat":"quant-ph","authors_text":"Jes\\'us Casado-Pascual, Sigmund Kohler","submitted_at":"2026-01-09T13:21:44Z","abstract_excerpt":"We investigate the Floquet spectrum of a detuned, driven two-level system and show that it exhibits exact quasienergy crossings when the detuning is an integer multiple of the energy quantum of the driving field. This behavior can be explained by a hidden time-nonlocal parity, which allows the Floquet modes to be classified as even or odd. Then a generic feature is the emergence of exact crossings between quasienergies of different parity. A constructive proof of the existence of the symmetry is based on a scalar recurrence relation. Moreover, we present a general scheme for its numerical comp"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"We investigate the Floquet spectrum of a detuned, driven two-level system and show that it exhibits exact quasienergy crossings when the detuning is an integer multiple of the energy quantum of the driving field. This behavior can be explained by a hidden time-nonlocal parity, which allows the Floquet modes to be classified as even or odd.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The model is restricted to a driven two-level system whose equations permit a scalar recurrence relation that directly reveals the parity; the hidden symmetry may not survive or be detectable in the same way for generic multi-level or nonlinear systems without the numerical scheme.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Exact quasienergy crossings occur in detuned driven two-level systems at integer multiples of the drive frequency due to a hidden time-nonlocal parity symmetry proven by scalar recurrence.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"A hidden time-nonlocal parity symmetry produces exact quasienergy crossings in driven two-level systems when detuning is an integer multiple of the drive quantum.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"bdcb2d7623e2c788a2151c3f8e2fe48af2ef6fce9573e3ee058f80c81f1efd3e"},"source":{"id":"2601.05783","kind":"arxiv","version":2},"verdict":{"id":"1960e7d7-4eab-4655-ab04-0e7b742c1c0e","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-16T16:06:03.578436Z","strongest_claim":"We investigate the Floquet spectrum of a detuned, driven two-level system and show that it exhibits exact quasienergy crossings when the detuning is an integer multiple of the energy quantum of the driving field. This behavior can be explained by a hidden time-nonlocal parity, which allows the Floquet modes to be classified as even or odd.","one_line_summary":"Exact quasienergy crossings occur in detuned driven two-level systems at integer multiples of the drive frequency due to a hidden time-nonlocal parity symmetry proven by scalar recurrence.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The model is restricted to a driven two-level system whose equations permit a scalar recurrence relation that directly reveals the parity; the hidden symmetry may not survive or be detectable in the same way for generic multi-level or nonlinear systems without the numerical scheme.","pith_extraction_headline":"A hidden time-nonlocal parity symmetry produces exact quasienergy crossings in driven two-level systems when detuning is an integer multiple of the drive quantum."},"references":{"count":22,"sample":[{"doi":"","year":1965,"title":"Solution of the Schrödinger equation with a Hamiltonian periodic in time","work_id":"1141f800-7d6b-4257-8efb-8d5b3b212321","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":1973,"title":"Steady states and quasiener- gies of a quantum-mechanical system in an oscillating field","work_id":"e6dc6282-81c5-4272-8ec9-d2fc0cce6d0c","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":1998,"title":"Driven quantum systems","work_id":"bd4576e9-ef62-442f-9cef-a54ffc290c5f","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":1991,"title":"Coherent destruc- tion of tunneling","work_id":"6482d66c-25ec-454c-8944-40cbd90f8e6c","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":1992,"title":"Local- ization in a driven two-level dynamics","work_id":"beb87767-82b1-4d6e-b743-a86248a1c9b3","ref_index":5,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":22,"snapshot_sha256":"2358fbd83084dbf66fecd838fd0ba66962dc2745f8ae480d50d23f816800071d","internal_anchors":0},"formal_canon":{"evidence_count":1,"snapshot_sha256":"c9103c4add2d2970b4a374d745c2d3435aef5b78fffdd54165274b72a74ad93e"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}