Polarisability of a confined multisubband electron gas with exchange and correlation interactions

The Singwi-Sjölander-Tosi-Lang approximation to the dielectric response of a 3D electron gas was designed to include exchange and correlation effects. This paper presents the formal extension to a low dimensionality, confined electron gas having a multisubband spectrum of one electron states. The quasi 1D case (quantum wire) is explicitly considered. It is seen that the analytical properties of the polarisability change quite significantly when manybody interactions are switched on.