School of Physics Thesis Dissertation Defense

Presenter:        Kaiyue Wang 

Title:                   Dynamics in an Ultracold Quantum Gas System for Mixtures 

Date:                  Tuesday, July 2, 2024

Time:                   1:30 p.m.  

Location:           Howey Physics Building, N201/202

Virtual Link:     https://gatech.zoom.us/j/96697760181?pwd=1rB9RGPf7pEw4oqK7b7Cr3CgmH8sSX.1

 Committee members: 

Dr. Colin Parker, School of Physics, Georgia Institute of Technology (advisor)

Dr. Carlos Sa de Melo, School of Physics, Georgia Institute of Technology 

Dr. Zhigang Jiang, School of Physics, Georgia Institute of Technology 

Dr. Xueda Wen, School of Physics, Georgia Institute of Technology

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

Abstract:

Quantum simulation with ultracold atoms is a popular and fast developing method for testing theories in different complex physical systems, such as in solid states, elementary particles and chemistry. The ultracold gas system offers a platform that is clean and controlled. We constructed a mixture system involving two atom species: Cs and Li, of large mass imbalance and different statistics, aiming at simulating the interaction between electrons and impurities in materials, which are believed to give rise to different electric conductivity and magnetism behaviors described by the Kondo Problem and RKKY theory. The system combines the optics and atom source of Cs system with an existing Li platform, where the Cs source is a portable module featuring a custom 2D-MOT (Magneto-Optical Trap). 

In the talk, I will also present our experiments on dynamics of a Li molecular BEC in a shaken optical lattice, in which we observed an unexpected continuous bifurcation in momentum space caused by the modified dispersion. We demonstrate how the bifurcation can be understood through GPE (Gross Pitaevskii Equation) and simulations, and its implication on a soliton enabled through interactions.