Phase gate for a photonic quantum network

Abstract

We give a fully quantum description of a simple model for a quantum phase gate which could be used for quantum communication in future optical quantum networks. The carriers of information are modelled as two-photon wavepackets which interact with an atom inside a two port cavity in a polarization-dependent manner. Owing to this interaction the different polarization states of the wavepackets suffer phase shifts which are intensity dependent. This process is well known as the Kerr effect.