Realization of a photonic CNOT gate sufficient for quantum computation
  We report the first experimental demonstration of a quantum controlled-NOT gate for different photons, which is classically feed-forwardable. In the experiment, we achieved this goal with the use only of linear optics, an entangled ancillary pair of photons and post-selection. The techniques developed in our experiment will be of significant importance for quantum information processing with linear optics. 
Sara Gasparoni, Jian-Wei Pan, Philip Walther, Terry Rudolph and Anton   Zeilinger