Enhancing coupling coefficient in a hybrid nanotoroid–nanowire system

Enhancing light–matter interaction in cavity quantum electrodynamics has aroused widespread interests in on-chip quantum information processing. Here, we propose a hybrid nanotoroid–nanowire system to enhance photon–exciton interaction. A nanoscale gap is formed by placing a dielectric nanowire close to a dielectric nanotoroid, where the coupling coefficient between photon and emitter can achieve 5.55 times of that without nanogap. Meanwhile, the cavity loss and spontaneous emission of the emitter will remain at a small value to guarantee the realization of strong coupling. The method might hold promise for the research of nanophotonics,quantum optics, and novel optical devices.