Quantum Lunch Seminar Series
Speaker: Daniel Leykam
Abstract: Holding your phone in a different way can be a simple fix for poor reception because an antenna's radiation efficiency depends on the local environment. The local environment plays a similarly important role in optimising the efficiency of quantum light sources, but the length scales (nanometres rather than centimetres) and materials (silicon rather than metals) involved are very different, making this a much more challenging problem. Recent studies have shown that fine-tuned arrays of silicon nanoparticles can increase the radiation efficiency from quantum light sources by orders of magnitude. I will discuss how this giant enhancement can be understood as a photonic flat band resonance which emerges due to competition between short- and long-range coupling effects and surprisingly involves fine-tuning of modes below the light line. This effect would not have been captured in previous simplified models that assume an infinite periodic environment, which predict these modes do not radiate at all. Our findings showcase the importance of taking multiple light scattering into account in the design of next-generation nanophotonic light sources.