Central to NQIT’s goal is the ability to interconnect multiple small-scale quantum processors, which requires a reliable interface between atoms and photons. The challenge here is to engineer interactions between atoms and photons, as the quantum information is usually lost before it can be transferred from the moving qubit (the photon) to the stationary qubit (the atom). This prevents us from building an efficient network of quantum processors without using further tricks. We use devices called optical cavities (or simply cavities) to enhance the interaction between atoms and photons.
The NQIT team at Sussex University has successfully integrated an ion trap with an optical cavity. With this system, the information from the ion trap can be directly channelled to another quantum processor via an optical fibre.
Furthermore, the team at Sussex, together with collaborators at Southampton, have designed and created a novel cavity which substantially improves the efficiency of information transfer to 90%, from previously realised systems which have efficiencies of less than 30%.