The Department of Physics and Astronomy cordially invites all to attend a colloquium talk featuring Dr. Cheng Chin, James Franck Institute, Enrico Fermi Institute, Department of Physics, University of Chicago. Dr. Chen will present his talk “The Rise and Fall of Universality, and the Broccoli” on Tuesday, April 21, at 4:10 p.m. in Webster B17.
Please meet Dr. Chin and share in refreshments, 3:45-4:10 p.m. in the foyer on floor G above the lecture hall.
Abstract:
Universal behaviors have been identified in cold atoms in a broader context than in condensed matter systems. Examples include unitary gas, BEC-BCS crossover, quantum critical gas, and atoms in reduced dimensions. In these examples, scale invariance is frequently assumed, which leads to a tremendous simplification of both theoretical and experimental characterization. Taking
broccoli as an example to illustrate the universal behavior, we show that the information is only contained on the surface of a unit sphere in the parameter space. Remarkably, we discuss the breakdown of “scaling hypothesis” in a special case (unitary Bose gas), and how we can potentially remedy the situation with a complex dimension.
