A lithographically-defined quantum dot with sub-wavelength confinement of light

We present an optical cavity with deep sub-wavelength confinement of light in a region that simultaneously works as a quantum dot. The design is based on a dielectric membrane with a buried quantum well and restricts the electron and hole wave functions to the area of the optical hotspot in order to overcome the challenge of co-locating an optical cavity with a quantum emitter. Combined with proper surface passivation, this geometry points towards the deterministic fabrication of functional quantum dots in optical cavities by lithographic means.