We demonstrate laser-driven two-qubit and single-qubit logic gates with fidelities 99.9(1)% and 99.9934(3)% respectively, significantly above the approximately 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 3.8μs and 520μs, and develop a theoretical error model which is consistent with the data and which allows us to identify the principal technical sources of infidelity.
@article{arxiv.1512.04600,
title = {High-fidelity quantum logic gates using trapped-ion hyperfine qubits},
author = {C. J. Ballance and T. P. Harty and N. M. Linke and M. A. Sepiol and D. M. Lucas},
journal= {arXiv preprint arXiv:1512.04600},
year = {2016}
}
Comments
1 trap, 2 ions, 3 nines. Detailed write-up of arXiv:1406.5473 including single-qubit gate data also