@phdthesis{12121,
  author = {Xin Xie},
  title = {Precise Calibrations of Few-Body Physics in Potassium-39: Experiment and Theory},
  abstract = {Ultracold atoms provide a versatile toolbox for the study of diverse quantum phenomena. The minimal platform to present quantum mechanics is at single particle level. Two-particle inter-ference effects such as Hanbury Brown-Twiss are a consequence of the particle statistics. Exotic quantum effects in which statistics and interactions are combined appear in three-particle systems as elucidated by e.g. Efimov in the early 1970s. Efimov’s work can be further extended to four- or five-particle systems and applied to general dilute quantum gases in the weakly interacting regime. In the many-body context, it may also assist the analysis of quench dynamics in unitary gasses where perturbation theory breaks down.

A systematic study of few-body physics is made possible by the use of magnetic Feshbach resonances. One can greatly benefit from the improved experimental precision when comparing the observables to generic few-body models. In this thesis, I begin by describing the efforts we spent on achieving overall robustness and accuracy on our potassium-39 quantum gas machine, including the hardware upgrades we made for future scientific projects. Then following a brief review on the realization of Efimov physics in cold atoms, I expand on a series of scattering experiments we performed to understand few-body physics with effectively repulsive inter-particle interactions, as a complement to our previous investigations of the attractive-interaction regime. At the end, I combine our knowledge from both regimes together to discuss the global picture of Efimov physics in homonuclear systems at a beyond proof-of-principle level.},
  year = {2020},
  journal = {Department of Physics},
  volume = {Ph.D.},
  pages = {199},
  month = {2020-05},
  publisher = {University of Colorado Boulder},
  address = {Boulder},
}