Construction of a ytterbium and lutetium ion trap and quantum control for multi-partite entanglement

Abstract

The technology of linear ion traps are constantly innovating with increasingly varying atomic species being trapped in more scalable systems. In some iterations, multiple species can be confined, offering advanced computing capabilities such as sympathetic cooling. As the ion chains grow in size, the ion operations must scale with it, permitting universal quantum computation in larger qubit arrays. In this thesis, the design, construction and preliminary characterisation of a dual-species trapped-ion system is described. Additionally, an investigation into how entangling gates operate in these systems is performed. Laser setups at 355nm drive the spin-motion coupling in ytterbium ions to produce entanglement at high fidelities in longer chains. First, entangling gates are implemented in the ytterbium trapwith improvements to the control software. Primitive Mølmer-Sørensen gates are introducedand phase modulated gates using Q-CTRL’s graph based optimiser are implemented. Second, entanglement is computationally investigated in multipartite systems. Comparisons aredrawn between quantum control techniques such as laser modulation and Rabi rate imbalances are investigated.