Casimir-Polder interaction between an atom and a dielectric grating

Ana M. Contreras-Reyes, Romain Guérout, Paulo A. Maia Neto, Diego A. R. Dalvit, Astrid Lambrecht, Serge Reynaud

Published 2010-10-01, updated 2010-11-23Version 2

We develop the scattering approach to calculate the exact dispersive Casimir-Polder potential between a ground-state atom and a rectangular grating. Our formalism allows, in principle, for arbitrary values of the grating amplitude and period, and of the atom-grating distance. We compute numerically the potential for a Rb atom on top of a Si grating and compare the results with the potential for a flat surface taken at the local atom-surface distance (proximity force approximation). Except for very short separation distances, the potential is nearly sinusoidal along the direction transverse to the grooves.