Nonlinear wave modulation in a quantum magnetoplasma

Amplitude modulation of ion-acoustic waves (IAW) in a magnetized electron-ion quantum plasma is investigated. For this purpose, a three-dimensional (3D) quantum magnetohydrodynamic model is considered in the limit of small mass ratio of the charged particles. By using the standard reductive perturbation technique, a 3D nonlinear Schrodinger equation containing the magnetic field and the quantum effects is derived. The importance of quantum corrections is described through a nondimensional parameter H which is proportional to quantum diffraction effects. Some important and new modulational instability criteria of 3D IAW, quite distinct from the classical one, are obtained and analyzed. (c) 2007 American Institute of Physics.