  Hexagonal boron nitride (h-BN), a prevalent insulating crystal for dielectric
and encapsulation layers in two-dimensional (2D) nanoelectronics and a
structural material in 2D nanoelectromechanical systems (NEMS), has also
rapidly emerged as a promising platform for quantum photonics with the recent
discovery of optically active defect centers and associated spin states.
Combined with measured emission characteristics, here we propose and
numerically investigate the cavity quantum electrodynamics (cavity-QED) scheme
incorporating these defect-enabled single photon emitters (SPEs) in h-BN
microdisk resonators. The whispering-gallery nature of microdisks can support
multiple families of cavity resonances with different radial and azimuthal mode
indices simultaneously, overcoming the challenges in coinciding a single point
defect with the maximum electric field of an optical mode both spatially and
spectrally. The excellent characteristics of h-BN SPEs, including exceptional
emission rate, considerably high Debye-Waller factor, and Fourier transform
limited linewidth at room temperature, render strong coupling with the ratio of
coupling to decay rates g/max({\gamma},\k{appa}) predicated as high as 500.
This study not only provides insight into the emitter-cavity interaction, but
also contributes toward realizing h-BN photonic components, such as
low-threshold microcavity lasers and high-purity single photon sources,
critical for linear optics quantum computing and quantum networking
applications.
