A single-atom optical quantum memory

A prerequisite for the realization of quantum networks is a coherent interface between flying and stationary qubits. So far, most of these interfaces have been based on the exchange of information between photons and collective atomic excitations. A promising alternative is the development of an interface between single photons and a single atom, employing an optical cavity to achieve sufficient coupling strength. This approach has fundamental advantages, as it allows for the individual manipulation of the atomic qubit and the implementation of a heralding scheme based on quantum non-demolition (QND) measurements of the atomic state.