Two-Component Bose-Einstein Condensation by

Date The final copy of this thesis has been examined by the signatories, and we find that both the content and the form meet acceptable presentation standards of scholarly work in the above mentioned discipline. Thesis directed by Prof. Eric Cornell Bose-Einstein condensates in dilute atomic gases have been around for almost 5 years now. The first experiments dealt with density related properties of the condensate – things like internal energy, collective excitations, and density profiles. All of these aspects are well described by a non-linear Schrodinger equation, in which the non-linearity arises from repulsive potentials between 87 Rb atoms that make up the condensate. While interesting in their own right, these experiments had little to do with the " strangeness " of a condensate as a macroscopic quantum object. In this work the new era of condensate physics is described. These are experiments mainly concerned with the quantum phase and coherence properties. We have constructed a robust system for creating internal-state superpositions, with the ability to image the interference between them. Our first observations show how condensates, initially created with a well-defined phase, remain coherent, unlike a sample of thermal atoms. We have devised schemes to spatially manipulate the relative phase between two condensates in unique ways which brings about very unexpected behavior. By choosing a very specific scheme we were able to create a vortex state and measure the unique 2π phase winding, making this a very simple system for utilizing quantum control. Dedication I dedicate this work to my wife Melanie, and my parents Ann and Robin. Melanie has really given up a lot so that I could follow physics. To her it meant living apart for many years, and always having to cut short our time together. She has been incredibly patient and supportive, and understanding when sometimes physics came first. I hope I can make it up to her. Sometimes people ask my parents where I got my talent at physics. For some reason people assume that it could not have been from a kindergarten teacher and a highschool geography teacher. Well, it was. From as early as I can remember, they motivated in me an interest in everything. They indulged me when ever they could afford to – things from archery to cadaver frogs. One of the first times I remember thinking about the world was when I asked my dad why the Battlestar …