Microwave trapped-ion quantum logic gates avoid spontaneous emission as a fundamental source of decoherence. However, microwave two-qubit gates are still slower than laser-induced gates and hence more sensitive to fluctuations and noise of the motional mode frequency. We propose and implement amplitude-shaped gate drives to obtain resilience to such frequency changes without increasing the pulse energy per gate operation. We demonstrate the resilience by noise injection during a two-qubit entangling gate with 9Be+ ion qubits. In absence of injected noise, amplitude modulation gives an operation infidelity in the 10−3 range.
@article{arxiv.1911.03954,
title = {Robust and resource-efficient microwave near-field entangling $^9$Be$^+$ gate},
author = {G. Zarantonello and H. Hahn and J. Morgner and M. Schulte and A. Bautista-Salvador and R. F. Werner and K. Hammerer and C. Ospelkaus},
journal= {arXiv preprint arXiv:1911.03954},
year = {2019}
}