Click here to download thesis: Spectroscopy and Dynamics of Laser-Cooled Ca+ Ions in a Penning Trap

Title: Spectroscopy and dynamics of laser-cooled Ca+ ions in a Penning trap


I report on work geared towards improving the efficiency of laser cooling in the Penning trap by manipulating the dynamics of the trapped ions. The wider aim of this project is to measure heating and decoherence rates in order to determine the feasibility of quantum information processing using ions trapped in a Penning trap. In this thesis I introduce the basic concepts of quantum information processing and its implementation in radiofrequency trapped-ion systems. I report on the difficulties currently being faced and how many of these obstacles can be circumvented by using Penning traps for ion confinement. Laser cooling in the Penning trap is usually rather inefficient because of the instability of the magnetron radial mode of motion. By extending an analytical model for laser cooling in the Penning trap I show that a technique called ‘axialisation’ can overcome this inefficiency by coupling the magnetron mode to another, stable radial mode. I present the results of an experiment to implement the axialisation technique and measure the improvement in laser cooling rates of calcium ions, and I assess the extent to which these results agree with those derived from our model. Finally I document our efforts to trap and cool single calcium ions in the Penning trap and discuss modifications to the experimental procedure that may make this possible in the near future.


Issue Date: October 2006

Supervisor: Thompson, Richard

                    Segal, Danny

Item Type:  Physics PhD Thesis