Photonic Controlled-NOT Gate Sufficient

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 only the use of linear optics, an entangled ancillary pair of photons, and postselection. The techniques developed in our experiment are of significant importance for quantum information processing with linear optics

Sara Gasparoni, Jian-Wei Pan, PhilipWalther, Terry Rudolph, and Anton Zeilinger

Realization of a Photonic Controlled-NOT Gate Sufficient for Quantum Computation

Phys.Rev.Lett. 93 (2004) 020504