Click here to download thesis: Studies of Laser Cooled Calcium Ions in the Penning and Combined Traps
Title: Studies of laser cooled calcium ions in the Penning and combined traps
This thesis details work performed on trapping and laser cooling calcium ions in a Penning trap. Only two species of ion (beryllium and magnesium) have previously been laser cooled in a Penning trap. Singly charged calcium ions have a signicantly different level structure to these two ions, but are similar to the heavier alkaline earth elements often used for frequency standards applications and quantum information processing in an rf trap. Laser cooling of calcium in the Penning trap requires the use of a novel laser scheme involving two cooling lasers.
Long term motivation of the work is discussed, with reference to quantum information processing. A brief literature review is also presented with an introduction to ion traps and their place within quantum information processing. Results are presented from the computer simulation of laser cooling in the four and two level atomic systems. This work uses the rate equation approach, iterating over discrete time steps to model the laser cooling. The novel aspects of laser cooling calcium (a four level system) are discussed with reference to the use of two cooling lasers.
Experimental work on setting up a Paul trap to laser cool calcium is discussed. New work on laser cooling calcium in a combined rf/Penning trap is presented. This is studied as a novel system in itself and as a stepping stone to the full Penning trap. Trapping and cooling in the Penning trap itself is demonstrated. Finally, work on stabilising a Ti:sapphire laser using the Pound Drever Hall method is presented. Future work is discussed, including the use of this laser for sideband cooling and addressing the narrow qubit transition.
Issue Date: 18 March 2003
Supervisor: Thompson, Richard
Item Type: Physics PhD Thesis