Dissipative hydrodynamic equation of a ferromagnetic Bose-Einstein condensate: Analogy to magnetization dynamics in conducting ferromagnets

TL;DR

This paper derives a dissipative hydrodynamic equation for ferromagnetic Bose-Einstein condensates, revealing an analogy to magnetization dynamics in conducting ferromagnets, and explores domain pattern dynamics influenced by particle currents.

Contribution

It introduces a dissipative hydrodynamic equation for ferromagnetic BECs that parallels the extended Landau-Lifshitz-Gilbert equation, linking condensate spin dynamics to magnetization behavior.

Findings

Demonstrates domain pattern dynamics with and without particle currents.

Shows the influence of currents on domain pattern formation.

Discusses characteristic lengths of domain walls with finite magnetization.

Abstract

The hydrodynamic equation of a spinor Bose-Einstein condensate (BEC) gives a simple description of spin dynamics in the condensate. We introduce the hydrodynamic equation of a ferromagnetic BEC with dissipation originating from the energy dissipation of the condensate. The dissipative hydrodynamic equation has the same form as an extended Landau-Lifshitz-Gilbert (LLG) equation, which describes the magnetization dynamics of ferromagnets interacting with spin-polarized currents. Employing the dissipative hydrodynamic equation, we demonstrate the magnetic domain pattern dynamics of a ferromagnetic BEC in the presence and absence of a current of particles, and discuss the effects of the current on domain pattern formation. We also discuss the characteristic lengths of domain patterns that have domain walls with and without finite magnetization.