Subradiance-enhanced excitation transfer between dipole-coupled nanorings of quantum emitters
Maria Moreno-Cardoner, David Plankensteiner, Laurin Ostermann, Darrick E. Chang, Helmut Ritsch · Physical Review A · 2019
A ring of dipole-coupled quantum emitters positioned at subwavelength distances possesses only a few radiant but many subradiant collective excitations with lifetimes growing exponentially with the atom number. These exhibit a three-dimensionally confined spatial radiation field pattern and form nanoscale high-$Q$ optical resonators. Tailoring size, orientation, and distance between two rings allows for increasing the ratio of coherent ring-to-ring energy transfer versus free-space emission by orders of magnitude. In particular, the more dark and delocalized over several sites are excitons, the higher is their fidelity for transport to a second ring.