QED with a spherical mirror
Abstract
We investigate the quantum electrodynamic (QED) properties of an atomic electron close to the focus of a spherical mirror. We first show that the spontaneous emission and excitedstate level shift of the atom can be fully suppressed with mirroratom distances of many wavelengths. A threedimensional theory predicts that the spectral density of vacuum fluctuations can indeed vanish within a volume λ^{3} around the atom, with the use of a fardistant mirror covering only half of the atomic emission solid angle. The modification of these QED atomic properties is also computed as a function of the mirror size, and large effects are found for only moderate numerical apertures. We also evaluate the longdistance groundstate energy shift (CasimirPolder shift) and find that it scales as (λ/R)^{2} at the focus of a hemispherical mirror of radius R, as opposed to the wellknown (λ/R)^{4} scaling law for an atom at a distance R from an infinite plane mirror. Our results are relevant for investigations of QED effects as well as freespace coupling to single atoms using highnumericalaperture lenses.
 Publication:

Physical Review A
 Pub Date:
 December 2010
 DOI:
 10.1103/PhysRevA.82.063812
 arXiv:
 arXiv:1009.2344
 Bibcode:
 2010PhRvA..82f3812H
 Keywords:

 12.20.m;
 42.25.p;
 37.30.+i;
 Quantum electrodynamics;
 Wave optics;
 Atoms molecules and ions in cavities;
 Quantum Physics
 EPrint:
 12 pages, 4 figures