Lagrangian approach and dissipative magnetic systems

Abstract

A Lagrangian is introduced which includes the coupling between magnetic moments $\mathbf{m}$ and the degrees of freedom $\mathbf{\sigma }$ of a reservoir. In case the system-reservoir coupling breaks the time reversal symmetry the magnetic moments perform a damped precession around an effective field which is self-organized by the mutual interaction of the moments. The resulting evolution equation has the form of the Landau-Lifshitz-Gilbert equation. In case the bath variables are constant vector fields the moments $\mathbf{m}$ fulfill the reversible Landau-Lifshitz equation. Applying Noether's theorem we find conserved quantities under rotation in space and within the configuration space of the moments.

12 pages, 1 figure

References in corpus (4)

• Nonlocal magnetization dynamics in ferromagnetic heterostructures
• Non-Markovian Dissipative Semiclassical Dynamics
• Fluctuation-dissipation considerations and damping models for ferromagnetic materials
• Pinning of magnetic domain walls in multiferroics

Cited by in corpus (1)

• Unquenched orbital angular momentum as the origin of spin inertia