We demonstrate that a single Rydberg excited Rb atom blocks excitation of a second atom located more than 10 Î¼m away. The observed probability of double excitation of < 20 % is consistent with a theoretical model of the Rydberg interaction. Recent progress towards using blockade to demonstrate a full two-atom CNOT gate will be presented. We will also discuss ideas for scaling to many qubits using collective encoding, and efficient multiqubit entanglement using asymmetric Rydberg interactions.
10 minute talk: Single-Photon Nonlinear Optics with Quantum Dots in Photonic Crystals