High-Fidelity Quantum Logic Gates Using Trapped-Ion Hyperfine Qubits.

By C. Ballance, T. Harty, Norbert Matthias Linke, M. Sepiol, D. Lucas. Physical Review Letters, 2014

639 citations recorded by the source corpus.

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 μs and 520 μs, and develop a theoretical error model which is consistent with the data and which allows us to identify the principal technical sources of infidelity.

Subfields: Artificial Intelligence, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/04c3d8b6fde46805f9b8921ac72c69e4d82237b0

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Citations in the corpus

Demonstration of the trapped-ion quantum CCD computer architecture (2020, methodology): “0(4) × 10 TQ gates (simultaneous RB) 8.”
Entanglement certification from theory to experiment (2018, background): “[246] C.”
Efficient Variational Quantum Simulator Incorporating Active Error Minimization (2016, background): “The best experiments to date [5,6] have reduced two-qubit gate infidelity to the range 10−3 to 10−4.”
Analysis of imperfections in the coherent optical excitation of single atoms to Rydberg states (2018, background): “Recent experimental efforts have shown an improvement in the fidelities of two-qubit gates [25,26], but they still remain below their theoretically predicted intrinsic fidelities [27,28] as compared to other experimental platforms, such as trapped ions [29,30] or superconducting qubits [31– 33].”
Quantum metrology with nonclassical states of atomic ensembles (2016, background): “A very high visibility of the parity signal has been reported with 40Ca+ (Benhelm et al., 2008) and 43Ca+ (Ballance et al., 2016) ions, see also Gaebler et al. (2016) for the high-fidelity generation of the two-qubit GHZ states with 9Be+ ions.”
Practical Quantum Error Mitigation for Near-Future Applications (2017, methodology): “Therefore, we estimate the cost of quantum error mitigation in the SWAP-test circuit, using the same error models in our numerical simulation and error rates achievable in ion trap experiments [28,29]; i.”
Quantum Computing in the NISQ era and beyond (2018, background): “With the best hardware we have now for controlling trapped ions [14] or superconducting circuits [15], the error rate per gate for two-qubit gates is above the .”
Materials challenges and opportunities for quantum computing hardware (2021, background): “5 to 100 ms (272, 277, 278), with single-qubit gates in the range of 10 ns to 5 ms (269, 279).”
Roads towards fault-tolerant universal quantum computation (2016, background): “Noise thresholds for the [[4, 2, 2]]-concatenated toric code.”
Deterministic generation of all-photonic quantum repeaters from solid-state emitters (2016, background): “These fidelities have been achieved in trapped ion systems [59, 60], for which spin-photon interfaces have also been demonstrated [61– 63].”
Quantum error correction: an introductory guide (2019, background): “There is currently no preferred qubit technology; a variety of physical systems are being explored for use as qubits, including photons [5,6], trapped ions [7–10], superconducting circuits [11–13] and spins in semiconductors [14–16].”