School of Physics Thesis Dissertation Defense

Jonathan Yang

Advisor: Dr. Colin Parker, School of Physics, Georgia Institute of Technology

Development of a Dual Cesium-133 and Lithium-6 Ultracold Atomic Gas System for Quantum Simulation

Date: Wednesday, November 12, 2025 

Time: 3:00pm - 5:00 pm 

Location: Pettit Microelectronics Building - 102A&B Conference Room Pettit

Meeting Link: http://tiny.cc/gjru001 (Microsoft Teams meeting)

Committee Members: 

Dr. Michael Chapman, School of Physics, Georgia Institute of Technology

Dr. Martin Mourigal, School of Physics, Georgia Institute of Technology

Dr. Brian Kennedy, School of Physics, Georgia Institute of Technology

Dr. Joshua Kretchmer, School of Chemistry & Biochemistry, Georgia Institute of Technology

Abstract: 

Quantum simulation offers a powerful approach towards studying quantum systems by means of emulating aspects of their properties and behavior using more controllable quantum systems. Such a simulator can be built from the experimental realization of ultracold atomic gases, whose setup permits a high degree of tunability and isolation from environmental noise. These features make the ultracold gas setup a versatile platform for exploring various quantum phenomena under clean and precisely controlled conditions.

This thesis focuses on the development of an ultracold atomic gas quantum simulator that facilitates the dual loading of bosonic cesium-133 and fermionic lithium-6 into the same ultra-high vacuum environment. A significant portion is thus dedicated to the experimental setup, detailing how the vacuum, optical, magnetic field, and control system setups integrate to form a unified apparatus. Additionally, the construction and characterization of our single-beam, five-trapping-region cesium 2D magneto-optical trap loading source module, designed for compactness and portability, is presented. The module is shown to reliably provide loading rates suitable for the requirements of the initial cooling stages.

To demonstrate the setup's effectiveness for single-species simulations, the dynamics of a lithium molecular Bose-Einstein condensate in a 1D shaken optical lattice across the BEC-BCS crossover is investigated. Complementary to these experiments is the exploration of experimental sequences that permit quasi-stable populations of bifurcated clusters facilitated by band hybridization. Finally, the preliminary efforts towards Raman sideband cooling of cesium and the conservative trap transport of both species are outlined, laying the groundwork for future quantum simulation experiments involving interspecies mixtures and interactions