{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"de7b77d8a77552648282f7d2f9d8e10ab0ca1b633f3ec56ec4da61bcc0c3165b","created":"2026-10-03T07:18:10Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011","c98bc365982ccf041c16ecefa2e9bbcf3c1ba198726ef75107771a435bdeb2b8"],"salt":"0a09115d587876e3a2076ded6a75ba390657827036151ef24ebf681de1d9db68","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"qi.tunneling-arrival-time.attoclock-delay","kind":"well-posed","literature_status":"contested","n":"1","parents":[{"note":"","parent_revision":"c98bc365982ccf041c16ecefa2e9bbcf3c1ba198726ef75107771a435bdeb2b8","relation":"special_case"}],"plain":"An attoclock uses a rotating laser field, like the hand of a clock, to time when an electron escapes an atom by tunneling. Experiments and analyses disagree on whether the escape takes a finite time or none.","posed_since":"2008","precise":"In elliptically polarized strong-field ionization of atomic hydrogen or helium, extract the tunneling delay $\\tau_T$ from the photoelectron momentum offset angle after subtracting the Coulomb deflection computed from the full time-dependent Schrodinger equation, and decide whether $\\tau_T = 0$ within resolution. A 2019 hydrogen experiment (Sainadh et al., Nature) reported tau_T below about $1.8e-18\\,\\mathrm{s}$.","problem_ref":null,"references":"","settled_by":"Agreement between calibrated attoclock measurements on hydrogen at several intensities and a clock-model prediction.","status_note":"2025 analyses (e.g. arXiv:2503.07859) continue to compare attoclock and Larmor-clock interpretations of strong-field tunneling.","title":"Is there a nonzero tunneling delay in strong-field ionization?","topic_ref":"358768349f8fe9b49e5942c4fef2bbf2a089805f474e2a5f2d52d216a641711f"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"4b15bf14f927784843fc0baa015776b80a06c45567c265054af6a8d6344ae509","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"23be4806f1732cd761d2e2734f9afa6610d0a23829682d115d33ef7cfdf25c20","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"KxTtpURTvFzhKyggyM_kD872EBQEX84JSJX6cEAdwEtehqf68imTQ0iOJ4ASK-x-rbttKKpDTnh4oioz-085Bg"},"schema":"pubphys.envelope/1"},"record_hash":"4b15bf14f927784843fc0baa015776b80a06c45567c265054af6a8d6344ae509","leaf_index":2059}