Transverse spin dynamics in a spin-polarized Fermi liquid

TL;DR

This paper derives linear equations for transverse spin dynamics in a weakly polarized Fermi liquid, revealing how temperature and polarization influence spin current relaxation and damping, with implications for understanding spin behavior at quantum levels.

Contribution

It introduces a general framework for transverse spin dynamics in polarized Fermi liquids derived from Landau-Silin kinetic equations, including temperature and polarization effects.

Findings

Finite transverse spin wave damping at T=0 for finite polarization

Temperature dependence of spin wave attenuation analogous to ultrasound absorption

Derived relaxation times for spin currents in polarized Fermi liquids

Abstract

The linear equations for transverse spin dynamics in weakly polarised degenerate Fermi liquid with arbitrary relationship between temperature and polarization are derived from Landau-Silin phenomenological kinetic equation with general form of two-particle collision integral. The temperature and polarization dependence of the spin current relaxation time is established. It is found in particular that at finite polarization transverse spin wave damping has a finite value at T=0. The analogy between temperature dependences of spin waves attenuation and ultrasound absorption in degenerate Fermi liquid at arbitrary temperature is presented. We also discuss spin-polarized Fermi liquid in the general context of the Fermi-liquid theory and compare it with "Fermi liquid" with spontaneous magnetization.