Dr. Han Fu, University of Chicago

Nonequilibrium dynamics in ultracold atomic systems

The experimental advances in preparing, controlling, and probing ultra-cold atomic systems provide powerful platforms for the study of non-equilibrium dynamics of quantum systems. When trapped particles are subjected to external driving or undergo quantum quenches, they display a rich variety of emergent phenomena not accessible in an equilibrium state.

In this talk, I will discuss my recent works on driven ultracold Bose atoms based on Gross-Pitaevskii numerical simulations. When applying an oscillating magnetic field to the system, interactions between Bose atoms will change periodically in time. We find that this leads to the formation of ‘Bose fireworks’, a fascinating physical phenomenon demonstrating driven-induced amplification of quantum fluctuations. When we modulate our trapping potentials, the energy spectrum of Bose atoms forms an effective band structure. In this case, we discover that Bose atoms can condense via a highly nontrivial process. These findings not only lead to our proposal of a new imaging method to probe ultracold Bose systems, but also reveal key aspects of thermalization in quantum many-body systems.