Electron spin motion in the delta-function pulse

TL;DR

This paper compares the electron spin dynamics described by the BMT equation and the Dirac equation's Wolkow solution in plane wave and delta-function pulse fields, highlighting differences in spin behavior predictions.

Contribution

It formulates the BMT equation for electron spin in delta-function pulses and compares it with the Wolkow solution, revealing discrepancies in spin evolution.

Findings

BMT and Wolkow solutions differ in spin predictions

Formulation of BMT in delta-function pulses

Comparison highlights limitations of each approach

Abstract

We formulate the Bargman-Michel-Telegdi (BMT) equation for electron spin motion in a plane wave and in the Dirac delta-function pulse. We compare the BMT solution with the Wolkow solution of the Dirac equation. The Wolkow solution for the spin is not identical with the solution following from the BMT .