Specific Heat of an Ultracold Bose Gas in a Harmonic Trap

Abstract

In this thesis we look at theory and experiments with the purpose of finding an experimental value for the specific heat of a Bose-Einstein condensate. First, we consider basic thermodynamics in a harmonic trap to define the concept of specific heat in this context. A model is constructed for the measurements and the measurements themselves are discussed. The first part of this thesis considers a time dependent magnetic trap to add energy to the system. We will predict this increase in energy by theory to be able to calculate the specific heat. This method turns out to be impractical and difficult to implement correctly experimentally. This is partly because of experimental difficulties but mainly because the process is not sufficiently understood. The second part concerns a laser beam illuminating the cloud to induce heating like in phase contrast imaging. Although theoretical predictions and experiments do not agree with one another, a scheme is laid out to be able to determine the specific heat from these experiments.