Giant interaction and entanglement of photons for deterministic optical quantum computation

Several novel schemes are studied which pave the way to deterministic quantum logic with photons. In one of such schemes, a weak (quantum) probe pulse, upon propagating through the medium, interacts with the forward and backward components of a weak signal pulse that is dynamically trapped in a photonic band-gap structure. In an alternative scheme, the two pulses propagate in the opposite directions in the EIT medium and interact with each other via strong, long-range dipole-dipole interaction between Rydberg states of the atoms. Both schemes are capable of implementing with high fidelity the conditional phase gate between two single-photon pulses, under physically realistic, experimentally accessible conditions.