Dynamics of Spin-Polarized Electron Liquid and Spin Pendulum

TL;DR

This paper explores the hydrodynamic behavior of spin-polarized electron liquids, revealing oscillations in spin polarization and drift current, and proposes methods to detect spin polarization via voltage measurements.

Contribution

It derives and analyzes hydrodynamic equations for spin-nonequilibrium electron systems, demonstrating possible spin oscillations and detection methods in conducting rings.

Findings

Oscillations of spin polarization are possible in inhomogeneous magnetic rings.

Low-decay spin and current oscillations occur in the hydrodynamic regime.

Voltage differences can reveal spin polarization in open circuits.

Abstract

We investigate the dynamics of spin-nonequilibrium electron systems for the case when normal electron collisions prevail over the other scattering processes and the "hydrodynamic flow" regime is realized. The hydrodynamic equations for the electron liquid have been obtained and analyzed. We demonstrate that oscillations of the spin polarization are possible in a conducting ring with inhomogeneous magnetic properties. These low-decay oscillations are accompanied by the oscillations of the drift current in the ring. We demonstrate also that the spin polarization of the electron density may be revealed via the voltage between the ends of the open circuit with an inhomogeneous spin polarization. The effect may be observed both in the hydrodynamic and diffusive regimes.