Individual-qubit addressing is a prerequisite for many instances of quantum information processing. We demonstrate this capability on trapped-ion qubits with microwave near-fields delivered by electrode structures integrated into a microfabricated surface-electrode trap. We describe four approaches that may be used in quantum information experiments with hyperfine levels as qubits. We implement individual control on two 25Mg+ ions separated by 4.3 micrometer and find spin-flip crosstalk errors on the order of 10^(-3).
@article{arxiv.1210.6407,
title = {Individual-Ion Addressing with Microwave Field Gradients},
author = {U. Warring and C. Ospelkaus and Y. Colombe and R. Jördens and D. Leibfried and D. J. Wineland},
journal= {arXiv preprint arXiv:1210.6407},
year = {2014}
}