Collective coupling of randomly dispersed oscillators with cavities filled with zero-index metamaterials

In cavity quantum electrodynamics, it is hard to enhance the coupling strength between quantum dot (QD) and cavity, owing to the limited choice of QDs and the positional uncertainty brought by the inhomogeneous cavity fields. In this paper, we randomly distribute N oscillators with oscillating strength G=G <Subscript>0</Subscript> into a cavity filled with a zero-index metamaterial (ZIM). Because of the enhanced uniform fields, each oscillator couples to the field maximum and the N oscillators are equivalent to one oscillator with effective N G <Subscript>0</Subscript>. This provides a way to enhance the coupling strength just by adding the number of QDs. Both simulation and experiment demonstrate the adjustable coupling strength in ZIM-filled cavities. Copyright EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2014