Spin dynamics in Kapitza-Dirac scattering of electrons from bichromatic laser fields

TL;DR

This study investigates how electron spins evolve during Kapitza-Dirac scattering in bichromatic laser fields, revealing spin-dependent Rabi oscillations and identifying conditions for maximum spin effects.

Contribution

The paper provides a detailed numerical and analytical analysis of spin dynamics in Kapitza-Dirac scattering with bichromatic laser fields, highlighting the role of electron spin and identifying regimes of maximal spin oscillations.

Findings

Electron spin undergoes Rabi-like oscillations during scattering.

Maximum spin oscillation amplitude occurs at specific parameters.

Spin-dependent effects are also briefly discussed for protons.

Abstract

Kapitza-Dirac scattering of nonrelativistic electrons from counterpropagating bichromatic laser waves of linear polarization is studied. The focus lies on the electronic spin dynamics in the Bragg regime when the laser fields possess a frequency ratio of two. To this end, the time-dependent Pauli equation is solved numerically, both in coordinate space and momentum space. Our numerical results are corroborated by analytical derivations. We demonstrate that, for certain incident electron momenta, the scattering crucially relies on the electron spin which undergoes characteristic Rabi-like oscillations. A parameter regime is identified where the Rabi oscillations reach maximum amplitude. We also briefly discuss spin-dependent Kapitza-Dirac scattering of protons.