Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Particle Accelerator Conference (PAC)

Stern-gerlach force on a precessing magnetic moment

M. Conte, Alfredo U. Luccio, M. Pusterla

Published Jan 1, 2007• 1 citation
Publisher

Abstract

Use of the Stern-Gerlach force for attaining the spin- states separation of a particle beam is reconsidered in a new method where the magnetic moments are made to precess, at variance with a previously considered case where the magnetic moment conserves its direction in space.
DOI
10.1109/pac.2007.4440548

Related papers

Relativistic Stern-Gerlach Interaction in an RF Cavity

M. Conte, Alfredo U. Luccio, M. Pusterla

The general expression of the Stern-Gerlach force is deduced for a relativistic spin-1/2 particle which travels inside a time varying magnetic field. This result was obtained either by means of two Lorentz boosts or starting from Dirac's equation. Then, the utilization of this interaction for attaining the spin states separation is reconsidered in a new example using a new radio-frequency arrangement.

arXiv:0907.2161•Jul 13, 2009•0 citations

The Relativistic Stern-Gerlach Force

Ch. Tschalaer

The relativistic Lagrangian for a spinning particle in an electromagnetic field is derived from the known Lagrangian in the particle's rest frame. The resulting relativistic Stern-Gerlach and Thomas precession forces on the particle are then derived from the Lagrangian in the laboratory frame. In particular, the longitudinal component of this combined Stern-Gerlach-Thomas force does not contain a term proportional to gamma-squared as was claimed in a previous derivation [1].

arXiv:0802.0154•Feb 1, 2008•1 citation

Stern-Gerlach Effect for Electron Beams

Herman Batelaan, T. J. Gay, J. J. Schwendiman

The conflict between Bohr's assertion that the magnetic moment of the electron cannot be measured with experiments based on the concept of classical trajectories, and the measurement of the magnetic moment of electrons in a modified Penning trap by Dehmelt et al. has led us to reevaluate other implications of Bohr's assertion. We show that, contrary to the analysis of Bohr and Pauli, the assumption of classical trajectories in a Stern-Gerlach--like device can result in a high degree of spin separation for an electron beam. This effect may persist within a fully quantum-mechanical analysis. The magnetic fields considered are such that a tabletop Stern-Gerlach electron spin filter is feasible.

Physical Review Letters•Dec 8, 1997•82 citations

Paradox in the classical treatment of the Stern–Gerlach experiment

Preben Alstrøm, Poul Georg Hjorth, R. D. Mattuck

Most textbook authors assume that the force on a magnetic moment sent into a Stern–Gerlach apparatus, is exclusively in the direction of the magnetic field. Hence they conclude that classically one should expect a continuous distribution of particles along a line in the field direction, on a screen placed behind the apparatus. However, it is easily shown that, because the divergence of the field is zero, there is in fact an equally large force transverse to the field direction. This would lead to an isotropic distribution of particles on the screen, in contradiction to the above conclusion. The paradox is resolved by taking into account the torque on the magnetic moment. This produces a rapid precession about the field direction, causing the transverse force to average out and thus giving the usual textbook result.

American Journal of Physics•Aug 1, 1982•26 citations

Spin precession and energy conservation

Onuttom Narayan

In this paper, we examine the precession of a spin in a magnetic field, treating the particle and the applied magnetic field as a single closed system whose energy is conserved. Through two simple examples, it is shown that the standard expression for spin precession emerges only indirectly, and as a first-order approximate result. For the first example, deviations from the first-order result are easy to obtain, and are familiar from Stern-Gerlach spin separation. For the second example, deviations from the first-order result are not practically possible to obtain. Beyond these two examples, it is also shown within a semiclassical approach that the standard expression for spin precession in a magnetic field is always valid to first order, irrespective of how the Hamiltonian depends on other dynamical variables of the system.

Physical Review A•Sep 5, 2000•0 citations

The Relativistic Stern-Gerlach Interaction and Quantum Mechanics Implications

P. Cameron

The time varying relativistic Stern‐Gerlach force, which acts over a charged particle endowed with a magnetic moment, is deduced from the Dirac Hamiltonian finding its coincidence with the classical expression. Possible drawbacks related to the Heisenberg uncertainty principle are discussed.

AIP conference proceedings•Jan 1, 2003•2 citations
The conflict between Bohr's assertion that the magnetic moment of the electron cannot be measured with experiments based on the concept of classical trajectories, and the measurement of the magnetic moment of electrons in a modified Penning trap by Dehmelt et al. has led us to reevaluate other implications of Bohr's assertion. We show that, contrary to the analysis of Bohr and Pauli, the assumption of classical trajectories in a Stern-Gerlach--like device can result in a high degree of spin separation for an electron beam. This effect may persist within a fully quantum-mechanical analysis. The magnetic fields considered are such that a tabletop Stern-Gerlach electron spin filter is feasible.
Most textbook authors assume that the force on a magnetic moment sent into a Stern–Gerlach apparatus, is exclusively in the direction of the magnetic field. Hence they conclude that classically one should expect a continuous distribution of particles along a line in the field direction, on a screen placed behind the apparatus. However, it is easily shown that, because the divergence of the field is zero, there is in fact an equally large force transverse to the field direction. This would lead to an isotropic distribution of particles on the screen, in contradiction to the above conclusion. The paradox is resolved by taking into account the torque on the magnetic moment. This produces a rapid precession about the field direction, causing the transverse force to average out and thus giving the usual textbook result.
In this paper, we examine the precession of a spin in a magnetic field, treating the particle and the applied magnetic field as a single closed system whose energy is conserved. Through two simple examples, it is shown that the standard expression for spin precession emerges only indirectly, and as a first-order approximate result. For the first example, deviations from the first-order result are easy to obtain, and are familiar from Stern-Gerlach spin separation. For the second example, deviations from the first-order result are not practically possible to obtain. Beyond these two examples, it is also shown within a semiclassical approach that the standard expression for spin precession in a magnetic field is always valid to first order, irrespective of how the Hamiltonian depends on other dynamical variables of the system.