title: Individual-ion addressing with microwave field gradients.
abstract: 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  μm and find spin-flip crosstalk errors on the order of 10(-3).
authors.affiliation: Time and Frequency Division, National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA. ulrich.warring@physik.uni-freiburg.de
authors.forename: U
authors.initials: U
authors.lastname: Warring
authors.forename: C
authors.initials: C
authors.lastname: Ospelkaus
authors.forename: Y
authors.initials: Y
authors.lastname: Colombe
authors.forename: R
authors.initials: R
authors.lastname: Jördens
authors.forename: D
authors.initials: D
authors.lastname: Leibfried
authors.forename: D J
authors.initials: DJ
authors.lastname: Wineland