DIELECTRIC FUNCTION AND PLASMON DISPERSION-RELATION OF A QUASI-2-DIMENSIONAL ELECTRON-GAS

In this paper we generalize the method suggested by Lee and Spector to calculate the dielectric function of a quasi-two-dimensional electron gas without strict restriction on the wave vector q, the conducting l ayer thickness d, and the dielectric constants of the conducting and s urrounding media epsilon, epsilon(1) epsilon(2). In the case of a thin layer tile plasmon dispersion equation obtained by means of the diele ctric function is solved exactly to get the dispersion relation of the collective excitations. We compare our exact solution to tile approxi mated result of Aharonian et al. and find that tile latter is valid on ly for very small values of qd.