{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"07b33c76831f6ce46b2e409cce67c69247f4ab7b6edff55fcb901bf9a2298650","created":"2026-10-03T07:17:53Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"19ba61ab572cbbc001353052fd20dbb6ae4f3108f22eecb67262aec695455701","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"amo.attosecond-electron-dynamics.solid-hhg-mechanism","kind":"phenomenon","literature_status":"contested","n":"1","parents":[],"plain":"An intense infrared laser shining on a crystal makes it emit light at many multiples of the laser frequency (high harmonics). Two pictures compete: electrons accelerating within one energy band, or electrons and holes recombining across the band gap.","posed_since":"2011","precise":"Bulk or monolayer crystals (ZnO, SiO2, GaSe, MoS2) driven by a mid-infrared field with Keldysh parameter $\\gamma < 1$ below the damage threshold. Quantity: the fraction of the harmonic yield in each order from the interband polarization (electron-hole recollision) versus the intraband current (nonparabolic band motion, Bloch-like oscillation), as a function of order, field strength and wavelength. An answer is an experimental observable that separates the two contributions unambiguously (harmonic phase, ellipticity or two-color response) in at least one material, matched by a parameter-free microscopic calculation.","problem_ref":null,"references":"","settled_by":"Phase-resolved harmonic measurements in a well-characterized crystal compared with ab initio time-dependent calculations that include propagation through the sample.","status_note":"Different materials and drive wavelengths have been reported to favor different dominant mechanisms; no unified microscopic account exists as of 2024.","title":"Interband versus intraband currents in high-harmonic generation from solids","topic_ref":"0df42c165abe2c701f655081b1ae2c457e3434bf87099b8b980410a52274fe98"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"183e79026db85b21406f5df4c36a6c7d3635be9ca1f4246146875d83810df5d8","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"2b246ed061d53591821a5186f75940baa3c6293f9d8baf9a7be346e7bfa3494d","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"DwV4zjKTj6Bm4-Wmk0iCNvnPzslj83cAe4LYpGicl_or6__dJ4xdSAm62jOlwk3NHZoGxFbVM05EOK3T0VFoDg"},"schema":"pubphys.envelope/1"},"record_hash":"183e79026db85b21406f5df4c36a6c7d3635be9ca1f4246146875d83810df5d8","leaf_index":369}