Addressed single-qubit gates for microwave-driven ions

Trapped-ions are a promising platform for quantum computing as they can form fundamentally identical qubits with long coherence times. Quantum logic gates are often performed using lasers but can also be driven by microwave fields for which the technology is cheaper, more reliable, and hence easier to scale up. However, due to the centimetre wavelength of microwaves, the radiation cannot be focused to a small spot size as with a laser. This complicates the addressing of individual qubits within a cluster of ions confined in the same potential well. Here, we demonstrate a novel electronic microwave control method to implement addressed single-qubit gates in such a register with high speed and fidelity. We benchmark errors of 1.5x10^-6 and 3.4x10^-5 per single-qubit gate when addressing a single ion alone or within a register of two ions respectively.