Pure many-body interactions in colloidal systems by artificial random light fields

Abstract

We propose a method to generate pure many-body interactions in colloidal systems by using optical forces induced by random optical fields with an optimized spectral energy density. To assess the feasibility in general settings, we develop a simple model for Lorentzian electric and magnetic dipole response. An optimization procedure is then introduced to design the spectral energy density of the random field that minimizes pair interactions at constant electromagnetic energy density. We conclude that, under rather general circumstances, it is possible to effectively cancel pair interactions within a range of distance. Hence a colloid can be driven to interact exclusively through many-body interactions