Abstract

The realization of quantum networks and long distance quantum communication rely on the capability of generating entanglement between separated nodes. This can be achieved if the separated nodes generate indistinguishable photons, independently of the physical processes on which they are based [1,2]. We demonstrate the compatibility of two different sources of single photons: a single atom and four-wave mixing in a cold cloud of atoms. The four-wave mixing process in a cloud of cold ⁸⁷Rb generates photon pairs. The cascade level scheme used ensures the generation of heralded single photons with exponentially decaying temporal envelope [3]. The temporal shape of the heralding photons matches the shape of photons emitted by spontaneous decay but for the coherence time, shortened because of the collective effects in the atomic cloud [4].

© 2015 IEEE