Polaritonic Contribution to the Casimir Energy between two Graphene Layers

TL;DR

This paper investigates how surface polaritons influence the Casimir energy between two graphene layers, revealing a distance-dependent transition from attractive to repulsive force and showing polaritonic effects are negligible at small separations.

Contribution

It provides a detailed calculation of polaritonic contributions to the Casimir energy in graphene, highlighting their impact on force sign change and asymptotic behavior.

Findings

Casimir force changes from attractive to repulsive with increasing distance.

Polaritonic contribution is negligible at small separations.

The study offers a parametric approach for dispersion relation calculations.

Abstract

We study the role of surface polaritons in the zero-temperature Casimir effect between two graphene layers that are described by the Dirac model. A parametric approach allows us to accurately calculate the dispersion relations of the relevant modes and to evaluate their contribution to the total Casimir energy. The resulting force features a change of sign from attractive to repulsive as the distance between the layers increases. Contrary to similar calculations that have been performed for metallic plates, our asymptotic analysis demonstrates that at small separations the polaritonic contribution becomes negligible relative to the total energy.