Control of Spin Polarization through Recollisions

TL;DR

This paper explores how recollision dynamics in xenon atoms, under linearly polarized light, can generate and influence spin polarization of photoelectrons, revealing ultrafast spin-flip processes linked to the ion's spin-orbit interaction.

Contribution

It demonstrates that ultrafast recollision dynamics induce spin polarization and flips in photoelectrons, a phenomenon previously overlooked in recollision-based models.

Findings

Spin polarization emerges when measuring photoelectrons in coincidence with ions.

Ultrafast recollision dynamics can cause spin flips in photoelectrons.

Effects occur within the dipole approximation.

Abstract

Using only linearly polarized light, we study the possibility of generating spin-polarized photoelectrons from xenon atoms. No net spin polarization is possible, since the xenon ground state is spin-less, but when the photoelectron are measured in coincidence with the residual ion, spin polarization emerges. Furthermore, we show that ultrafast dynamics of the recolliding photoelectrons contribute to an apparent flipping of the spin of the photoelectron, a process that has been completely neglected so far in all analyses of recollision-based processes. We link this phenomenon to the ``spin--orbit clock'' of the remaining ion. These effects arise already in dipole approximation.