Oscillations in the spontaneous emission rate of atoms in a dielectric slab: Effects of photon closed orbits

The spontaneous emission rate of an atom in dielectric slabs is shown to exhibit multiperiodic oscillations when the system scale is varied. These oscillations are calculated using quantum electrodynamics and analyzed using ideas from closed-orbit theory. The extracted frequencies in the emission rates by Fourier transform agree well with actions of short photon closed orbits. The oscillations in the spontaneous emission rates are interpreted as interferences of emitted photon propagating on closed orbits leaving and returning to the emitting atom. This study provides a new understanding of the spontaneous emission process for atoms in the presence of environments.