High-Fidelity Transport of Trapped-Ion Qubits through an X-Junction Trap Array

We report reliable transport of Be-9(+) ions through an X junction in a 2D trap array that includes a separate loading and reservoir zone. During transport the ion's kinetic energy in its local well increases by only a few motional quanta and internal-state coherences are preserved. We also examine two sources of energy gain during transport: a particular radio-frequency noise heating mechanism and digital sampling noise. Such studies are important to achieve scaling in a trapped-ion quantum information processor.