High-Harmonic Spectroscopy as a Tool to Extract Hole Location in Particle-Like Charge Migration

We will show that particle-like charge migration [1] can be effectively tracked using high-harmonic spectroscopy when used in a pump-probe, frequency-matched configuration, such that the location of the hole at any given time can be accurately extracted from the delay-dependent harmonic spectra [2]. Due to the attochirp of the harmonic radiation, different harmonic frequencies see distinct molecular landscapes upon recombination; thus, we observe a delay- and harmonic-frequency-dependent modulation of the HHG yield due to the CM. Using the semiclassical model of HHG as a guide, this modulation allows us to determine the absolute “time zero” at which the CM dynamics was initiated.

[1] Hamer, K. A. et al. (2022). Characterizing Particle-Like Charge-Migration Dynamics with High-Order Harmonic Sideband Spectroscopy. PRA 106, 013103.

[2] Hamer, K. A. et al. (2023). Tracking Particle-Like Charge Migration using Delay-Dependent High-Harmonic Spectroscopy. Manuscript in preparation.