Light propagation beyond standard optics in a uniform-density polarizable medium
Prof. Janne Ruostekoski, Lancaster University, UK
Leuchs-Russell Auditorium, A.1.500, Staudtstr. 2
The interaction of light with ensembles of resonant emitters is becoming increasingly important for both fundamental research and technological applications as experimentalists realize a growing number of such systems. We perform microscopic numerical simulations of light propagation in a uniform-density polarizable medium on an atom-by-atom basis. Comparisons between these essentially exact simulations for cold and dense atomic vapours and the predictions obtained from the standard electrodynamics of a polarizable medium (EDPM) reveal that the more than a century-old wisdom of conventional textbook optics can dramatically and qualitatively fail. The failure of EDPM is not due to quantum effects, but reflects emergent cooperative phenomena and strong light-induced correlations between the atoms. However, incorporating the effects of thermal motion in hot atom vapours or inhomogeneous resonance broadening restores the usual phenomenology of effective continuous medium electrodynamics. These strong cooperative interactions can be utilised in arrays of atoms and other dipolar emitters, e.g., in preparation of giant subradiant states.