Spin induced nonlinearities in the electron MHD regime

TL;DR

This paper investigates how electron spin influences the nonlinear behavior of whistler waves in plasma, deriving a nonlinear Schrödinger equation that incorporates spin effects and analyzing their significance under different plasma conditions.

Contribution

The study introduces a modified electron two-fluid model for electron MHD that includes spin effects and derives a nonlinear Schrödinger equation accounting for these effects.

Findings

Spin effects vary with plasma density, temperature, magnetic field, and wave frequency.

Spin influences the nonlinearity coefficients in whistler wave propagation.

Results are relevant for understanding plasma behavior in various astrophysical and laboratory settings.

Abstract

We consider the influence of the electron spin on the nonlinear propagation of whistler waves. For this purpose a recently developed electron two-fluid model, where the spin up- and down populations are treated as different fluids, is adapted to the electron MHD regime. We then derive a nonlinear Schrodinger equation for whistler waves, and compare the coefficients of nonlinearity with and without spin effects. The relative importance of spin effects depend on the plasma density and temperature as well as the external magnetic field strength and the wave frequency. The significance of our results to various plasmas are discussed.