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arXiv · 2305.03450

Breaking the entangling gate speed limit for trapped-ion qubits using a phase-stable standing wave

S. Saner·O. Băzăvan·M. Minder·P. Drmota·D. J. Webb·G. Araneda·R. Srinivas·D. M. Lucas·C. J. Ballance
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Abstract

All laser-driven entangling operations for trapped-ion qubits have hitherto been performed without control of the optical phase of the light field, which precludes independent tuning of the carrier and motional coupling. By placing $^{88}$Sr$^+$ ions in a $\lambda=674$ nm standing wave, whose relative position is controlled to $\approx\lambda/100$, we suppress the carrier coupling by a factor of $18$, while coherently enhancing the spin-motion coupling. We experimentally demonstrate that the off-resonant carrier coupling imposes a speed limit for conventional traveling-wave M{\o}lmer-S{\o}rensen gates; we use the standing wave to surpass this limit and achieve a gate duration of $15\ \mu$s, restricted by the available laser power.

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S. Saner, O. Băzăvan, M. Minder, P. Drmota, D. J. Webb, G. Araneda, R. Srinivas, D. M. Lucas, C. J. Ballance. 2023-05-05. Breaking the entangling gate speed limit for trapped-ion qubits using a phase-stable standing wave. https://doi.org/10.1103/physrevlett.131.220601

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