Technological Improvements for Linear Ion Trap Experiments

Synopsis

Laser-cooled, trapped ions are a highly controlled experimental system that allows one to engineer novel quantum states of both fundamental and practical interest. For a string of ions in a linear radio frequency (RF) Paul trap, the linear-zigzag structural phase transition is an intriguing system to investigate quantum dynamics near the critical point of a prototype second-order phase transition, including the preparation of superposition states of different structural configurations. This thesis focuses on two technological improvements required for studying the linear-zigzag structural phase transition in the quantum regime. The first is the development of a compact and cost-effective RF synthesizer setup to provide multiple modulation sources for the laser manipulation of ion strings. The functionality and limitations of a prototype design, based on Direct Digital Synthesizer (DDS) development boards with a microcontroller interface, are evaluated and future improvements are identified. The second part of this thesis focuses on the stabilization of the secular trap frequencies in a linear Paul trap, which is necessary to obtain a stable critical point for the studies of the linear-zigzag transition. To this end, this thesis presents the implementation of a Ramsey spectroscopic technique to measure the secular frequencies and presents the preliminary results from the stability tests.