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Identifying the Stern-Gerlach force of classical electron dynamics
Meng Wen1, Heiko Bauke1, Christoph H Keitel1
1Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
Scientific Reports
|August 23, 2016
Summary
Classical physics models for electron dynamics, like the Frenkel and Foldy-Wouthuysen models, are compared to quantum predictions. The Foldy-Wouthuysen model better describes electron spin dynamics in strong fields.
Area of Science:
- * Relativistic quantum mechanics
- * Classical electrodynamics
- * Particle physics
Background:
- * Classical theories describe electron relativistic dynamics using coupled equations for orbital motion and spin precession.
- * The Frenkel and Foldy-Wouthuysen models are commonly applied in physics.
- * Spin-dependent forces, such as Stern-Gerlach forces, are crucial in these models.
Purpose of the Study:
- * To benchmark the Frenkel and Foldy-Wouthuysen models against the Dirac equation for electron dynamics.
- * To evaluate the validity and limitations of classical theories in strong electromagnetic fields.
- * To compare predictions of how Stern-Gerlach forces affect electron orbital motion.
Main Methods:
- * Comparison of classical models (Frenkel, Foldy-Wouthuysen) with quantum dynamics from the Dirac equation.
- * Analysis of electron motion in strong electromagnetic fields, characteristic of high-intensity laser facilities.
- * Benchmarking spin-dependent forces (Stern-Gerlach forces) within classical frameworks.
Main Results:
- * Classical theories can yield differing or contradictory predictions for spin-induced orbital motion.
- * The Foldy-Wouthuysen model shows better qualitative agreement with the Dirac theory than the Frenkel model.
- * Identified discrepancies highlight the limits of classical descriptions in extreme conditions.
Conclusions:
- * The Foldy-Wouthuysen model offers a more accurate classical approximation for electron spin dynamics compared to the Frenkel model.
- * Experimental validation is crucial for refining classical theories describing spin-induced dynamics.
- * Understanding these limits is essential for applications involving high-intensity laser-plasma interactions.
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