Three Body Recombination and Photoassociative Ultracold Collisions Studied Using Translational Energy

摘要

In this work, a Rydberg atom imaging spectrometer to study individual collision events in an ultracold gas was developed. The apparatus achieved velocity resolution of 2.5 cm/s. This resolution allows all known ultracold collision processes to be resolved. The spectrometer was tested on low energy Rydberg atom collisions occurring in an ultracold gas of Cs atoms. To analyze this data, a procedure for calculating the interactions between high lying Rydberg states was developed. A parallel computer code to calculate these interactions was completed and implemented on a cluster machine (OSCER). The potentials were used to predict the results of the Rydberg atom collisions studied with the spectrometer. The theory and experiments were found to be in excellent agreement. The Rydberg interaction potentials are important for understanding and predicting the characteristics of dipole blockade which is important for quantum computation schemes that use atoms. Calculations were also completed on the Li trimer to describe 3-body recombination and other ways that molecules can form in ultracold gases. The goal of these calculations was to predict differential cross-sections for 3-body recombination so that future measurements with the imaging spectrometer that was built and tested on Rydberg collisions can be compared to this theory.