Attosecond high-harmonic interferometry probes orbital- and band-dependent dipole phase in magnesium oxide.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 42066095.
- Also identified by DOI 10.1126/sciadv.aeb4109 and PMC identifier 13134606.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Control over the spatial coherence, wavefront, and focusability of emitted light relies on understanding the intrinsic phase of the emission process, and vice versa; measuring the phase can provide insights about microscopic generation mechanisms. Using attosecond interferometry with phase-locked extreme ultraviolet (XUV) pulses, we directly measure the phase differences of XUV pulses emitted from two separate foci on the same solid sample that generate high harmonics at different driving intensities, allowing us to assess the intensity- and frequency-dependent dipole phase. Our results are supported by analytical, two-band, and full-band numerical theoretical models. The analytical approach benefits future solid-state high-harmonic generation studies, while the full numerical model details orbital- and band-resolved current contributions to the dipole phase. This research delivers combined quantitative measurement and rigorous theoretical description of the harmonic emission phase in solids.