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arXiv · 1406.5473

High-fidelity two-qubit quantum logic gates using trapped calcium-43 ions

C. J. Ballance·T. P. Harty·N. M. Linke·D. M. Lucas
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Abstract

We study the speed/fidelity trade-off for a two-qubit phase gate implemented in $^{43}$Ca$^+$ hyperfine trapped-ion qubits. We characterize various error sources contributing to the measured fidelity, allowing us to account for errors due to single-qubit state preparation, rotation and measurement (each at the $\sim0.1\%$ level), and to identify the leading sources of error in the two-qubit entangling operation. We achieve gate fidelities ranging between $97.1(2)\%$ (for a gate time $t_g=3.8μ$s) and $99.9(1)\%$ (for $t_g=100μ$s), representing respectively the fastest and lowest-error two-qubit gates reported between trapped-ion qubits by nearly an order of magnitude in each case.

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C. J. Ballance, T. P. Harty, N. M. Linke, D. M. Lucas. 2014-06-20. High-fidelity two-qubit quantum logic gates using trapped calcium-43 ions. https://doi.org/10.1103/physrevlett.117.060504

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