Strong superradiance of coherently coupled magnetic dipole emitters mediated by whispering gallery modes of a subwavelength all-dielectric cavity

The interaction of magnetic dipole (MD) emitters and common photonic cavities is usually weak, which partially due to the low near field enhancements cavities. Here, we show that whispering gallery modes (WGMs) a subwavelength dielectric cavity can not only greatly boost emission rate MD emitter but also bring efficient couplings between coherent emitters. In WGM cavity, maximal ({\gamma}max) single occurs at an antinode pattern. be affected by another one depending on response WGM. contribution reach {\gamma}max. Notably, cooperative does decay with distance in considered range high-quality feature contrast emission, absorption hardly mediated difference performances highly related excitation behaviors WGMs. Our results are important for enhanced light-matter interactions.