Enhanced chiral-sensitivity of Coulomb-focused electrons in strong field ionization

Abstract

Strong-field light-matter interactions initiate a wide range of phenomena in which the quantumpaths of electronic wavepackets can be manipulated by tailoring the laser field. Among the electronsreleased by a strong laser pulse from atomic and molecular targets, some are subsequently drivenback to the vicinity of the ionic core by the oscillating laser field. The trajectories of these returningelectrons are bent towards the core by the ionic potential, an effect known as Coulomb focusing.This process, studied over the past two decades, has been associated with the long range influenceof the Coulomb potential. Here we explore the structural properties of the Coulomb focusingphenomenon. Specifically, we numerically study the sensitivity of the returning electron dynamicsto the anisotropy of the ionic potential. We employ orthogonally polarized two-color strong fieldsand chiral molecules, whose asymmetric features lead to unambiguous fingerprints of the potentialon the freed electrons. The Coulomb-focused electrons show an enhanced sensitivity to chirality,related to an asymmetric attoclock-like angular streaking stemming from field-assisted scatteringof the electrons onto the chiral ionic potential. Anisotropic features of the ionic potential thusmonitor the motion of Coulomb-focused electrons throughout their returning paths, shedding lighton the structural properties of the interaction.