Spontaneous emission and level shifts in absorbing disordered dielectrics and dense atomic gases: A Green's function approach
- Abstract: Spontaneous emission and Lamb shift of atoms in absorbing dielectrics are discussed. A Green's-function approach is used based on the multipolar interaction Hamiltonian of a collection of atomic dipoles with the quantised radiation field. The rate of decay and level shifts are determined by the retarded Green's-function of the interacting electric displacement field, which is calculated from a Dyson equation describing multiple scattering. The positions of the atomic dipoles forming the dielectrics are assumed to be uncorrelated and a continuum approximation is used. The associated unphysical interactions between different atoms at the same location is eliminated by removing the point-interaction term from the free-space Green's-function (local field correction). For the case of an atom in a purely dispersive medium the spontaneous emission rate is altered by the well-known Lorentz local-field factor. In the presence of absorption a result different from previously suggested expressions is found and nearest-neighbour interactions are shown to be important.
Author: | Michael Fleischhauer |
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URN: | urn:nbn:de:hbz:386-kluedo-12071 |
Document Type: | Preprint |
Language of publication: | English |
Year of Completion: | 1999 |
Year of first Publication: | 1999 |
Publishing Institution: | Technische Universität Kaiserslautern |
Date of the Publication (Server): | 2001/07/02 |
Faculties / Organisational entities: | Kaiserslautern - Fachbereich Physik |
DDC-Cassification: | 5 Naturwissenschaften und Mathematik / 530 Physik |
Licence (German): | Standard gemäß KLUEDO-Leitlinien vor dem 27.05.2011 |