Casimir-Lifshitz interaction between dielectrics of arbitrary geometry:A dielectric contrast perturbation theory

摘要

The general theory of electromagnetic-fluctuation-induced interactions in dielectric bodies as formulated byDzyaloshinskii, Lifshitz, and Pitaevskii is rewritten as a perturbation theory in terms of the spatial contrast in(imaginary) frequency dependent dielectric function. The formulation can be used to calculate the Casimir-Lifshitz forces for dielectric objects of arbitrary geometry, as a perturbative expansion in the dielectric contrast,and could thus complement the existing theories that use perturbation in geometrical features. We find thatexpansion in dielectric contrast recasts the resulting Lifshitz energy into a sum of the different many-bodycontributions. The limit of validity and convergence properties of the perturbation theory is discussed using theexample of parallel semi-infinite objects for which the exact result is known.