Quantum switch for single photons based on semiconductor quantum dots – QSWITCH

The aim of the QSWITCH project is the realization of a quantum switch for single photons. This device is an ultimate version of a light switch where a single photon fixes the on or off state. The fabrication of this switch is based on a system in the strong coupling regime where a single quantum dot is embedded in the cavity mode of a photonic crystal. The device non-linearity stems from the anharmonicity of the quantum eigenstates spectrum with the number of photons in the cavity mode. This effect is referred to as photon blockade which is based on the fundamental quantum properties of cavity quantum electrodynamics. The implementation of this scheme in solid state is accessible thanks to the fermionic statistics of the excitations in a quantum dot and the high-quality factor of small mode volume photonic crystal nanocavities.