Many-body properties of a disordered charged Bose gas superlattice

We study some many-body properties of a disordered charged Bose gas (CBG) superlattice-an infinite array of CBG layers each of which containing disorder. The latter is assumed to cause collisions with the charged bosons, the effect of collisions being taken into account through a number-conserving relaxation time approximation incorporated within the random phase approximation (RPA) at T = 0. We go beyond the RPA and include a local-field correction G(q, q z) which is assumed to be collision independent, as an approximation. The resulting density-density correlation function is then used to calculate a number of many-body quantities of physical interest, e.g. (a) collective modes, (b) static structure factor, (c) energy-loss function, (d) plasmon density of states, and (e) groundstate energy. The effects of collisions on these quantities are discussed, and the results are compared with the corresponding results for an electron gas superlattice.