COLLECTIVE EXCITATIONS OF MAGNETOPLASMA IN SEMIINFINITE N-I-P-I SUPERLATTICES

A theoretical investigation has been made of the collective (bulk and surface) excitations in a semiinfinite n-i-p-i superlattice system in the presence of a magnetic field oriented perpendicular to the interfa ces and to the direction of propagation. The thicknesses of the consti tuent layers is assumed to be sufficiently large so that the quantum-w ell effects can be ignored. The material layers are characterized by f requency- and magnetic-field-dependent dielectric functions. The magne toplasma modes are defined by electromagnetic fields that are localize d at and decay exponentially away from the interfaces and from the end of the superstructure. The general dispersion relations are derived u sing a fully retarded theory in the framework of a transfer-matrix met hod. Numerical examples are presented for several illustrative cases.