Higher multipole surface plasmons, plasmon bands in periodic metallic heterostructures, and plasma modes of semiconductor superlattices

The electronic collective excitations are investigated for a number of different systems whose equilibrium electron density n0(z) is spatially varying. The relation between higher multipole surface modes, waveguide like plasma modes of a low electron density layer embedded in a high density host, and plasmon bands of periodic metallic heterostructures and semiconductor superlattices is pointed out. © 1984.