Magnetoacoustic cnoidal wave structures in degenerate plasma with separate spin electrons in oblique magnetic field

Abstract Fast and slow magnetoacoustic cnoidal waves in degenerate plasmas in the presence of an oblique magnetic field are investigated with an electrons’ fluid model where electrons’ spin-up (-down) states exist. The two separate equations of state for spin-up (-down) density states of electrons with the quantum tunneling effect due to Bohm potential are taken into account. The effect of magnetization current (in Maxwell equations) and energy (in electron momentum equations) due to two separate electrons’ spin is also included. The Korteweg–de Vries (KdV) equation with suitable boundary conditions is derived by applying a reductive perturbation technique. Nonlinear periodic (cnoidal) wave solution is obtained for fast and slow magnetoacoustic waves in magnetized degenerate plasma. It is found that dip structures of magnetic field perturbations are formed for nonlinear slow magnetoacoustic waves while hump structures are formed for nonlinear fast magnetoacoustic waves in dense plasmas. The effect of electron spin-up (-down) density states parameter ( κ ) on the propagation of slow and fast magnetoacoustic cnoidal waves and solitons are illustrated in numerical plots and is discussed in detail.