The propagation of linear waves in spin quantum magnetoplasmas

Jun Zhu - Wenda Guo - Xiaoshan Liu

School of Physics and Electronic Engineering, Shanxi University, Taiyuan, 030006, China

Abstract
A theoretical investigation on the propagation of linear waves in spin quantum magnetoplasmas is presented. Based on the quantum magnetohydrodynamic model, including the Bohm potential, the relativistic degeneracy pressure of electrons and the spin magnetization energy caused by the electron 1/2 spin effect and the Maxwell's equation modified by the spin current density, the dispersion equation for spin quantum magnetoplasmas is derived. Solving the dispersion equation in the case of propagation parallel or perpendicular to the background magnetic field, dispersion relations of left-handed wave, right-handed wave, upper hybrid wave, ordinary and extraordinary waves are derived, respectively. Research shows that Langmuir oscillations and upper hybrid oscillations can propagate in cold plasmas due to the Bohm potential and relativistic degeneracy pressure. Since the extraordinary wave consists of partial transverse and longitudinal waves, quantum effects can modify its dispersion relation. The modification of the dispersion relations by quantum effects is calculated with typical parameters of a dense astrophysical object, such as the pulsar magnetosphere. It is also confirmed that the pulsar magnetosphere is a real physical environment in which quantum effects need to be considered. Figs 3, Refs 30.