Photoelectric effect of helonium by an arbitrarily polarized XUV laser pulse

Abstract By means of quantum mechanical calculations, we investigate the Einstein’s photoelectric effect in helonium (HeH + ) molecule driven by an arbitrarily polarized XUV pulse of light. To examine the impact of the asymmetric initial electron distribution of the bound state on the photoelectron momentum distributions (PMDs) and the probability current densities (PCDs), we perform a comparative study for fixed-in-space H 2 or HeH + molecule, whose highest-occupied molecular orbital is symmetric or asymmetric. We find that the same pattern occurs in the PMD and PCD, with great sensitivities to the initial orbital symmetry, molecular orientation and light polarization state. Our simulations thus allow to watch the PMD arise asymptotically in the shape of the coordinate space PCD. In particular, when the light travels perpendicularly to the fixed-in-space H 2 molecule, a dipole is formed in the distributions for linear polarization (LP), while a yin-yanglike pattern exhibiting dichroism is created for circular polarization (CP). On the contrary, for aligned HeH + a LP pulse drives a large monopole, while a CP pulse transforms the distributions from yin-yanglike patterns to peculiar lung-like patterns including dichroism.