Casimir-Lifshitz Theory and Metamaterials

TL;DR

This paper generalizes Lifshitz theory to calculate Casimir forces involving magnetodielectric and anisotropic metamaterials, exploring conditions for repulsion and how material properties influence force sign and magnitude.

Contribution

It introduces a generalized theoretical framework for Casimir forces with complex metamaterials, highlighting the effects of magnetic dissipation, anisotropy, and frequency-dependent responses.

Findings

Casimir repulsion decreases with magnetic dissipation.

Small Drude background in metallic metamaterials can turn repulsive forces attractive.

Force sign is sensitive to optical anisotropy and magnetic response frequency dependence.

Abstract

Based on a generalization of the Lifshiftz theory we calculate Casimir forces involving magnetodielectric and possibly anisotropic metamaterials, focusing on the possibility of repulsive forces. It is found that Casimir repulsion decreases with magnetic dissipation, and even a small Drude background in metallic-based metamaterials acts to make attractive a Casimir force that would otherwise be predicted to be repulsive. The sign of the force also depends sensitively on the degree of optical anisotropy of the metamaterial, and on the form of the frequency-dependency of the magnetic response.