Collective excitations of magnetoplasma in truncated metallic superlattices

Abstract

We have studied the dispersion characteristics of the bulk and surface magnetoplasmons in a semi-infinite bimetallic superlattice structure. The thicknesses of the constituent layers are assumed to be sufficiently large so that the ``quantum-size effects'' can be neglected. The superlattice structure is subjected to an applied magnetic field taken to be parallel to the superlattice axis (or perpendicular to the interfaces). The material layers are characterized by the frequency- and magnetic-field-dependent dielectric tensors. The magnetoplasma modes (polaritons) are defined by the electric fields localized at and decaying exponentially away from the interfaces. In spite of the mathematical complexity, we have presented some analytical diagnoses in order to substantiate the asymptotic limits attained by the bulk bands and (some) surface modes, both for zero and nonzero magnetic fields. The numerical results are presented for a number of illustrative cases.