Cavity Quantum Electrodynamics with Epitaxial Quantum Dots

Much in physics is explained through an understanding of harmonic oscillation, but nonlinearity makes physics more exciting and greatly contributes for its many applications. Optical nonlinearities at the single-photon level are key ingredients for future photonic quantum technologies. Here we report unprecedented strong single-photon nonlinearities and single-photon switching on ultrafast timescales in epitaxial quantum dots strongly coupled to microcavities.