A Generalization of Electromagnetic Fluctuation-Induced Casimir Energy

Abstract

Intermolecular forces responsible for adhesion and cohesion can be classified according to their origins; interactions between charges, ions, random dipole-random dipole (Keesom), random dipole-induced dipole (Debye) are due to electrostatic effects; covalent bonding, London dispersion forces between fluctuating dipoles, and Lewis acid-base interactions are due to quantum mechanical effects; pressure and osmotic forces are of entropic origin. Of all these interactions, the London dispersion interaction is universal and exists between all types of atoms as well as macroscopic objects. The dispersion force between macroscopic objects is called Casimir/van der Waals force. It results from alteration of the quantum and thermal fluctuations of the electrodynamic field due to the presence of interfaces and plays a significant role in the interaction between macroscopic objects at micrometer and nanometer length scales. This paper discusses how fluctuational electrodynamics can be used to determine the Casimir energy/pressure between planar multilayer objects. Though it is confirmation of the famous work of Dzyaloshinskii, Lifshitz, and Pitaevskii (DLP), we have solved the problem without having to use methods from quantum field theory that DLP resorted to. Because of this new approach, we have been able to clarify the contributions of propagating and evanescent waves to Casimir energy/pressure in dissipative media.

Casimir effect modified surface energy of a nanocavity in homogeneous media

“…Lifshitz used Rytov's theory of fluctuational electrodynamics to determine the force between two semi‐infinite half‐spaces separated by a vacuum gap (a planar cavity). Recent works have shown that the generalization of Lifshitz theory can be applied not only to the multilayered media , but also to the objects of arbitrary shapes , such as ellipsoids , cylinders and cubes . In this work, we find the van der Waals contribution to pressure within a cavity of vapor, the electromagnetic properties of which is assumed to be identical with that of vacuum, in a homogeneous, isotropic, infinite liquid (see Fig.…”