Spin solitons in magnetized pair plasmas

TL;DR

This paper derives fluid equations incorporating electron and positron spin effects in magnetized pair plasmas, revealing new Alfvénic solitary structures governed by a modified KdV equation, relevant for astrophysical environments like pulsar magnetospheres.

Contribution

It introduces a novel set of fluid equations that include spin properties, leading to the discovery of new solitary wave structures in magnetized pair plasmas.

Findings

Discovery of spin-induced Alfvénic solitary structures.

These structures are governed by a modified KdV equation.

Quantum spin effects are essential for the existence of these structures.

Abstract

A set of fluid equations, taking into account the spin properties of the electrons and positrons in a magnetoplasma, are derived. The magnetohydrodynamic limit of the pair plasma is investigated. It is shown that the microscopic spin properties of the electrons and positrons can lead to interesting macroscopic and collective effects in strongly magnetized plasmas. In particular, it is found that new Alfvenic solitary structures, governed by a modified Korteweg-de Vries equation, are allowed in such plasmas. These solitary structures vanish if the quantum spin effects are neglected. Our results should be of relevance for astrophysical plasmas, e.g. in pulsar magnetospheres.