Chiral Spin Waves in Fermi Liquids with Spin-Orbit Coupling

TL;DR

This paper predicts and characterizes chiral spin wave modes in two-dimensional Fermi liquids with spin-orbit coupling, revealing their dynamics, spectrum, and potential experimental detection methods.

Contribution

It introduces the theoretical prediction of chiral spin waves in Fermi liquids with spin-orbit coupling using Landau theory and Klein-Gordon equations, a novel insight.

Findings

Chiral spin waves exist in 2D Fermi liquids with spin-orbit coupling.

The dynamics follow Klein-Gordon equations with effective masses.

Spin-chiral mode spectrum can be derived from Dyson equations.

Abstract

We predict the existence of chiral spin waves collective modes in a two-dimensional Fermi liquid with the Rashba or Dresselhaus spin-orbit coupling. Starting from the phenomenological Landau theory, we show that the long-wavelength dynamics of magnetization is governed by the Klein- Gordon equations. The standing-wave solutions of these equations describe "particles" with effective masses, whose magnitudes and signs depend on the strength of the electron-electron interaction. The spectrum of the spin-chiral modes for arbitrary wavelengths is determined from the Dyson equation for the interaction vertex. We propose to observe spin-chiral modes via microwave absorption of standing waves confined by an in-plane profile of the spin-orbit splitting.