Special Colloquium
Department of Physics, NCU
Cooperative spontaneous emissions: Superradiance, subradiance, and far-field scattering
Speaker
Dr. Hsiang-Hua Jen (任祥華)
Institute of Physics,Academia Sinica
Date 2017.12.26 (Tue)
Time 11:00
Place S4-625
Abstract: Recent progress on the collective light scattering and subradiant fluorescence measurements opens up a renewed study of strong and collective light-matter interactions in neutral atoms. This cooperative phenomenon of the reduced or prolonged spontaneous emission time results from a long-range dipole-dipole interaction in a confined atomic system. When the atoms are close enough to each other and become aware of each other’s presence through exchanging photons in the dissipation process, the decay rate can be collectively enhanced along with the associated frequency shift in the emission.
We propose a set of subradiant states which can be prepared and detected in a one-dimensional optical lattice.
We find that the decay rates are highly dependent on the spatial phases imprinted on the atomic chain, which allows systematic investigations of the subradiance in fluorescence experiments. We also investigate the light scattering of the super- and subradiant states which can be prepared by the excitation of a single photon which carries an orbital angular momentum (OAM). With this helical phase imprinted on the stacked ring of atomic arrays, the subradiant modes show directional side scattering in the far-field, allowing for light collimation and quantum storage of light with OAM.