2025/01/19 by Q. Z. Lv, Michael Klaiber, Lv, Q. Z. +7
Biochemistry, Genetics and Molecular Biology · Engineering · Materials Science · #Advanced Electron Microscopy Techniques and Applications #Atomic Physics (physics.atom-ph) #Electron and X-Ray Spectroscopy Techniques #FOS: Physical sciences #Photocathodes and Microchannel Plates #Quantum Physics (quant-ph)
paper · pdf · doi:10.48550/arxiv.2501.11144
openalex publication_date 2025/01/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Previous attoclock experiments measuring the photoelectron momentum distribution (PMD) via strong-field ionization in an elliptically polarized laser field have shown anomalously large offset angles in the nonadiabatic regime with large Keldysh parameters (γ). We investigate the process theoretically in the complete range of ellipticity (ε) and large range of γ, employing numerical solutions of time-dependent Schrödinger equation and nonadiabatic classical-trajectory Monte Carlo simulations matched with the under-the-barrier motion via the nonadiabatic strong field approximation. We show the formation of low-energy structures (LES) at any ellipticity value when the Keldysh parameter is sufficiently large. Three regimes of the interaction in the (ε-γ)-space of parameters are identified via the characteristic PMD features. The significant modification of the recollision picture in the nonadiabatic regime, with so-called anomalous and hybrid slow recollisions, is shown to be behind the LES, inducing extreme nonlinear Coulomb bunching in the phase-space in the polarization plane. Our findings elucidate subtle features of the attosecond electron dynamics in strong-field ionization at extreme conditions and indicate limitations on attosecond imaging.