Eur. Phys. J. D (2015) 69: 99
https://doi.org/10.1140/epjd/e2015-50898-8

Regular Article

Fluctuations of the Casimir potential above a disordered medium

Laboratoire Kastler Brossel, UPMC-Sorbonne Universités, CNRS, ENS-PSL Research University, Collège de France, 4 Place Jussieu, 75005 Paris, France

^a e-mail: cherroret@lkb.upmc.fr

Received: 19 December 2014
Received in final form: 10 February 2015
Published online: 7 April 2015

Abstract

We develop a general approach to study the statistical fluctuations of the Casimir potential felt by an atom approaching a dielectric disordered medium. Starting from a microscopic model for the disorder, we calculate the variance of potential fluctuations in the limit of a weak density of heterogeneities. We show that fluctuations are essentially governed by scattering of the radiation on a single heterogeneity, and that they become larger than the average value predicted by effective medium theory at short distances. Finally, for denser disorder we show that multiple scattering processes become relevant.