Effect of a strong laser on spin precession

TL;DR

This paper investigates how intense laser fields influence the spin precession of charged particles, revealing a resonance phenomenon where spin flips occur at specific laser intensities due to relativistic effects.

Contribution

It extends the semiclassical analysis of spin dynamics beyond the electric dipole approximation, identifying a laser-induced spin flip resonance dependent on field strength and particle properties.

Findings

Identification of a spin flip resonance at specific laser intensities.

Demonstration of the impact of relativistic corrections on spin evolution.

Analysis beyond the electric dipole approximation.

Abstract

The semiclassical dynamics of a charged spin-1/2 particle in an intense electromagnetic plane wave is analyzed beyond the electric dipole approximation and taking into account the leading relativistic corrections to the Pauli equation. It is argued that the adiabatic spin evolution driven by a low intensity radiation changes its character drastically as an intensity of a laser is increasing. Particularly, it is shown that a charged particle exposes a spin flip resonance at a certain pick value of a laser field strength, which is determined by a particle's gyromagnetic ratio.