Observation of long range Rydberg blockade

Interactions between Rydberg states of neutral atoms are a promising approach for fast and long range quantum gates. We demonstrate that a single Rydberg excited Rb atom blocks excitation of a second atom located more than $10~\mu\rm m$ away. The observed probability of double excitation of $< 20~\%$ is consistent with a theoretical model of the Rydberg interaction. Progress towards using blockade to demonstrate a CNOT gate as well as ideas for efficient creation of multiqubit entanglement will be presented.