Colloquium: Physics & Astronomy – Qingze Guan

About the event

The Department of Physics and Astronomy invites all to a colloquium featuring Qingze Guan, University of Oklahoma, Physics and Astronomy. Dr. Guan will present their talk, “Watching ultracold two-body collisions one at a time.”

Meet for refreshments before the lecture at 3:45 – 4:10 p.m. in the foyer on floor G above the lecture hall.

Abstract:

Access to single particle momenta provides new means of studying the dynamics of few interacting particles. In a joint theoretical and experimental effort, we observe and analyze the effects of a finite number of ultracold two-body collisions on the relative and single-particle densities by quenching two ultracold atoms with initial narrow wave packet into a wide trap with inverted aspect ratio. The experimentally observed spatial oscillations of the relative density are reproduced by a parameter- free zero-range theory and interpreted in terms of cross-dimensional flux. We theoretically study the long time dynamics and find that the system does not approach its thermodynamic limit. The set-up can be viewed as an advanced particle-collider that allows one to watch the collision process itself.