title: Nonlinear ion-acoustic solitons in a magnetized quantum plasma with arbitrary degeneracy of electrons.
abstract: Nonlinear ion-acoustic waves are analyzed in a nonrelativistic magnetized quantum plasma with arbitrary degeneracy of electrons. Quantum statistics is taken into account by means of the equation of state for ideal fermions at arbitrary temperature. Quantum diffraction is described by a modified Bohm potential consistent with finite-temperature quantum kinetic theory in the long-wavelength limit. The dispersion relation of the obliquely propagating electrostatic waves in magnetized quantum plasma with arbitrary degeneracy of electrons is obtained. Using the reductive perturbation method, the corresponding Zakharov-Kuznetsov equation is derived, describing obliquely propagating two-dimensional ion-acoustic solitons in a magnetized quantum plasma with degenerate electrons having an arbitrary electron temperature. It is found that in the dilute plasma case only electrostatic potential hump structures are possible, while in dense quantum plasma, in principle, both hump and dip soliton structures are obtainable, depending on the electron plasma density and its temperature. The results are validated by comparison with the quantum hydrodynamic model including electron inertia and magnetization effects. Suitable physical parameters for observations are identified.
authors.affiliation: Physics Institute, Federal University of Rio Grande do Sul, CEP 91501-970, Avenida Bento Gonçalves 9500, Porto Alegre, RS, Brazil.
authors.forename: Fernando
authors.initials: F
authors.lastname: Haas
authors.affiliation: Theoretical Physics Division (TPD), PINSTECH, P.O. Nilore, Islamabad 44000, Pakistan.
authors.forename: Shahzad
authors.initials: S
authors.lastname: Mahmood