SPONTANEOUSLY EMITTING ATOM IN FRONT OF A 2-SLIT INTERFEROMETER

A fully quantum-mechanical description of the spontaneous emission fro m an excited two-level atom placed in front of a two-slit interferomet er is given. Global modes of the electromagnetic field in a two slit s ystem are derived within the Kirchhoff-Huygens diffraction approximati on, serving as a base for the field quantisation. The standard Fermi's golden rule, supplemented by a factor coming from the nontrivial mode structure caused by the presence of the two-slit interferometer, is u sed to show that interference results from the position-dependent coup ling between the atom and different field modes of the system.