Nonadiabaticity-induced abnormal Coulomb-focusing effect in an orthogonally polarized two-color laser field
Phys. Rev. A 113, 043113 – Published 10 April, 2026
DOI: https://doi.org/10.1103/zvms-z65d
Abstract
The Coulomb focusing effect on different sub-laser-cycle electrons, i.e., prepeak direct and postpeak rescattering electrons, is theoretically investigated using the exact solution of three-dimensional (3D) time-dependent Schrödinger equation (TDSE), as well as semiclassical simulations based on both adiabatic and nonadiabatic models in the orthogonally polarized two-color laser field. By comparing their photoelectron momentum distributions (PMDs) along the light-propagation direction, we find that the nonadiabatic tunneling effect plays a critical role in modulating the relative strength of the Coulomb focusing between the direct and rescattering electrons, showing a pronounced phase dependence. Remarkably, within a specific phase window, this relative strength even reverses, leading to an abnormal behavior where the direct electrons experience stronger Coulomb focusing. Resorting to component-separated nonadiabatic models, we successfully uncover its underling dynamic mechanisms. We further demonstrate that this abnormal behavior can be clearly extracted from the TDSE-calculated PMD, paving the way for its direct experimental detection.
