Implementation of optical tweezers in trapped ion systems for quantum computation

This thesis makes a systematic study of the addition of optical tweezers to trapped-ions systems for quantum simulation and computation.
We start by describing the Paul trap and ion motion within. We use optical tweezers to modify the mode spectrum and engineer spin-interactions, and quantify the tweezer-induced differential Stark shift on the qubit transition.
We propose a fast gate relying on tweezers to generate the state-dependence. A set of electric field pulses followed by periods of free evolution produces the target phase gate.
We detail the experimental setup, where we trap and manipulate different isotopes of Ytterbium, and select our microwave qubit within the hyperfine manifold of ground state 171Yb+. The trap geometry, vacuum chamber and laser orientation are presented. We describe cooling, shelving, state preparation and detection, laser systems, characterise trap frequencies, photon collection efficiency and radial and axial micromotion. We study state preparation and detection and determine the qubit’s frequency spectrum. Rabi oscillations and Ramsey fringes are shown, and we estimate our coherence time. We show spin echo sequences which can be used to measure the effect of a high-power tweezer.
We present a method to align a resonant tweezer on a single ion, using the latter as a probe for tweezer position, size and intensity, and detail its optimisation routine. We show how light scattering phenomena affect the tweezer and align more than one tweezer on the ions.
We conclude by proposing the next steps to optimise the high-power, non-resonant tweezer and discuss further setup requirements.