03-07-2017 14:30  Electro-optics and Microelectronics Seminar

Abstract - Enhancement of Superradiant Emission of Quantum Sources by Coupling to Material Inhomogeneities

I develop a theory for cooperative spontaneous emission of an ensemble of quantum emitters near matter, which is consistent with the quantum mechanical treatment originally performed by Dicke. The model considers both the effects of building of inter-emitter correlation over time through virtual transitions via the common field, and of geometry-induced spatial correlation. The presence of material inhomogeneity alters the Local Density of States in accordance with classical electromagnetism, resulting in modified decay rate and emission intensity for the entire ensemble relative to those of spontaneous emission in free space. A silver sphere is found to augment the rate and emission amplitude of the collective emission by approximately 500% for certain settings, but as inter-emitter interactions are found to take place mainly through lossy surface plasmon modes, a significant portion of the energy invested in excitement of the system is lost. Epsilon-near-zero metamaterial spheres are shown to enhance the radiative inter-emitter transitions for certain geometries by effectively shortening the distance between them, resulting in more than tenfold stronger and faster emission with negligible absorption loses.

Location: 1061
Speaker: Amir Sivan
Affiliation: Dept. of Electrical Engineering Technion Back