Nonlinear magnetosonic waves in spin 1/2 quantum plasma

Abstract

Nonlinear magnetosonic waves in degenerate plasmas are discussed by using the spin-1/2 quantum magnetohydrodynamics model. Spin effects are incorporated via spin force and macroscopic spin magnetization current. Using both the reductive perturbation and Sagdeev potential techniques to derive the nonlinear evolution equations. In the limited amplitude a KadomstevPetviashvili equation and in arbitrary amplitude an energy integral equation involving Sagdeev potential are derived. The effects of electron spin magnetization, quantum diffraction and plasma statistic (temperature degeneracy) are discussed on the profile of solitons. The importance of the work relevant to compact astrophysical bodies is pointed out.

Group velocity of extraordinary waves in superdense magnetized quantum plasma with spin-1/2 effects

“…Here, the term M ¼ n e l 2 B B=k B T Fe is the macroscopic spin magnetization in a completely degenerate Fermi gas (so-called Pauli spin magnetization). 19,33 Where, l B ¼ e h=2m e is the Bohr magneton and k B is the Boltzmann constant. h is Planck's constant divided by 2p.…”

“…(8) is associated with the quantum Bohm potential gradient (corresponding to the quantum corrections in the density fluctuations) and the second is the spin magnetization force due to the electron-1/2 spin effects, respectively. The spin evolution equation for spin quantum plasmas is given by 15,19 ds dt ¼ 2l B h ðs  BÞ:…”

“…From Eqs. (18), (19), (21), and (22), the following dispersion relation of the quantum plasmas is derived where, x pe and x ce are the electron plasma and the electron gyro-frequencies, respectively, and k 2 B ¼ h=2m e x ce is an auxiliary quantity.…”

“…Nonlinear magnetosonic waves in degenerate plasmas were discussed using the spin-1/2 QMHD model in Ref. 19, and the authors studied both limited and arbitrary amplitude magnetosonic soliton. Ren, Wu, and Chu 20 derived the dispersion of linear waves in uniform cold quantum plasma without the spin-1/2 effects.…”