High Fidelity Quantum Logic Gates Using Trapped Ion Hyperfine Qubits.
We demonstrate laser driven two qubit and single qubit logic gates with respective fidelities 99.9(1) and 99.9934(3) significantly above the 99% minimum threshold level required for fault tolerant quantum computation, using qubits stored in hyperfine ground states of calcium 43 ions held in a room temperature trap. We study the speed fidelity trade off for the two qubit gate, for gate times between 3.8 ms and 520 ms, and develop a theoretical error model which is consistent with the data and which allows us to identify the principal technical sources of infidelity.
Physical review letters