Microscopic theory of the noncontact van der Waals interaction : Application to layered systems

In this paper we introduce an efficient method for the calculation of the noncontact van der Waals interaction between two metallic slabs of arbitrary thicknesses and densities. Because of the numerical resolution, the method enables the detailed examination of transition from the classical to the intermediate region of the vdW interaction. We also demonstrate how this new microscopic formulation reduces to the classical Lifshitz formula for the van der Waals interaction. This method is applied to calculate the interaction between various planar systems and compared with some previous results.