High-harmonic spectroscopy of transient two-center interference calculated with time-dependent density-functional theory

François Mauger; Paul M Abanador; Timothy D Scarborough; Timothy T Gorman; Pierre Agostini; Louis F DiMauro; Kenneth Lopata; Kenneth J Schafer; Mette B Gaarde

doi:10.1063/1.5111349

High-harmonic spectroscopy of transient two-center interference calculated with time-dependent density-functional theory

Struct Dyn. 2019 Jul 16;6(4):044101. doi: 10.1063/1.5111349. eCollection 2019 Jul.

Authors

François Mauger¹, Paul M Abanador¹, Timothy D Scarborough², Timothy T Gorman², Pierre Agostini², Louis F DiMauro², Kenneth Lopata³, Kenneth J Schafer¹, Mette B Gaarde¹

Affiliations

¹ Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA.
² Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA.
³ Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, USA.

Abstract

We demonstrate high-harmonic spectroscopy in many-electron molecules using time-dependent density-functional theory. We show that a weak attosecond-pulse-train ionization seed that is properly synchronized with the strong driving mid-infrared laser field can produce experimentally relevant high-harmonic generation (HHG) signals, from which we extract both the spectral amplitude and the target-specific phase (group delay). We also show that further processing of the HHG signal can be used to achieve molecular-frame resolution, i.e., to resolve the contributions from rescattering on different sides of an oriented molecule. In this framework, we investigate transient two-center interference in CO₂ and OCS, and how subcycle polarization effects shape the oriented/aligned angle-resolved spectra.