Fully integrated chip-based quantum computing

Trapped ions constitute near-perfect qubits with unrivalled quantum logic performance. Microfabricated "chip" traps are a promising avenue for scaling up to the large numbers of qubits required for future quantum computers. We previously made the first demonstration of a complete set of elementary qubit operations with high fidelity (above 99.5%) using chip traps [Harty et al., PRL 2014 and 2016], where the coherent qubit control was by performed by microwave electronic techniques. Our second-generation chip trap system, which operates at moderate cryogenic temperatures (10K-50K) to reduce noise, has the necessary performance to achieve logic gates with greater than 99.9% fidelity, at significantly faster speeds than our first-generation system. However, the optical control (still needed for qubit state prep and readout) is still provided by bulk optics, severely limiting the scalability of the technology.