PhysRevA.68.033813.pdf (106.94 kB)
Methods of asymptotic analysis in cavity quantum electrodynamics
journal contributionposted on 2023-06-07, 22:23 authored by Claudia Eberlein, Shin-Tza Wu
The energy-level shift of a ground-state atom in front of a nondispersive dielectric half-space is calculated by quantizing the electric field by means of a normal-mode expansion and applying second-order perturbation theory to the electric-dipole Hamiltonian muE. It is shown that the contributions to this shift coming from traveling and from evanescent waves can be combined into a single expression which lends itself readily to asymptotic analysis for large atom-surface separations, while in the opposite asymptotic regime when the atom is close to the surface the combined expression is less convenient. Employing a Greens-function formalism instead of the normal-mode expansion leads directly to the combined formula, and in that case it is advantageous to be able to apply the same transformation backwards and split the energy shift into a sum of distinct contributions corresponding to different physical processes. The analysis serves to shed light on common sources of error in the literature and paves the way for the study of more complicated models in cavity quantum electrodynamics.
- Published version
JournalPhysical Review A
Department affiliated with
- Physics and Astronomy Publications
NotesAn explicit transformation is found between the energy level shifts calculated with two different atom-field couplings in cavity QED, which is an enormous simplification for asymptotic calculations. The work was initiated by me and done in collaboration with a former graduate student.
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