Coupling the Radial Vibrational Modes of Mixed Barium-Ytterbium Chains for Quantum Computing

Abstract

The advantages of mixed species ion chains may be essential to scaling a quantum computer; however, using them requires a better understanding of mixed species ion trapping and manipulation than we currently posses. In this thesis I perform measurements of the eciency of sympathetic cooling of mixed barium-ytterbium ion chains. After initially measuring temperatures, I investigate the vibrational mode couplings. I discover parameters for a linear Paul trap for which 2-Ba-2-Yb chains are cooled to near the Doppler limit, and for which their vibrational modes are coupled well enough to perform entangling gates. I nd numerically that these parameters should scale well to at least ten ions. Instabilities of the trap and of the 1762 nm `shelving' laser system are systematics on my measurements, so I also characterize various noise sources related to the experiment.