Quantum Plasma Effects in the Classical Regime

TLDR

Quantum effects in plasmas are usually considered significant only when the temperature‑to‑density ratio is small. This study challenges that assumption by examining the role of electron spin in plasma dynamics. The authors model the plasma as a multicomponent fluid with separate spin‑up and spin‑down electron populations. Analysis of Alfvén wave soliton propagation shows that quantum effects persist even at relatively high temperatures, and the implications of these findings are discussed.

Abstract

For quantum effects to be significant in plasmas it is often assumed that the temperature over density ratio must be small. In this paper we challenge this assumption by considering the contribution to the dynamics from the electron spin properties. As a starting point we consider a multicomponent plasma model, where electrons with spin-up and spin-down are regarded as different fluids. By studying the propagation of Alfv\'en wave solitons we demonstrate that quantum effects can survive in a relatively high-temperature plasma. The consequences of our results are discussed.