Method and apparatus for quantum information processing using entangled neutral-atom qubits

We have invented a method to generate entanglements between two qubits or multiple qubits by using "Rydberg-dressed blockade." Each qubit is encoded inside the hyperfine sublevels of each atom. By shining an off-resonance Rydberg excitation laser to the atoms, which have sufficiently short inter-atomic distances, the interactions between ground-state atoms are generated and some transitions between the states of multiple-qubit basis are blockaded. This leads to an efficient way to generate entangled states, such as Bell state, W state, cat state, GHZ state, etc. by simply turning on a qubit transition pulse. The system is then naturally evolving into the desired entangled state. This new method has not been proposed before, and we have demonstrated 2-qubit entanglement in our laboratory using our invention. Such technology can be very useful for quantum information and quantum computing based on neutral atoms.