  We present the first demonstration of a CNOT gate using neutral atoms. Our
implementation of the CNOT uses Rydberg blockade interactions between neutral
atoms held in optical traps separated by >8 \mu\rm m. We measure CNOT
fidelities of F=0.73 and 0.72 using two different gate protocols, and show by
measurement of parity oscillations that the gate can be used to generate
two-atom states with fidelity at the threshold for entanglement. We anticipate
that the long range nature of the Rydberg interaction will be attractive for
future extensions of this work to multi-qubit systems.
