Nate Gemelke
James Franck Institute
University of Chicago
Exploring Quantum Statistics With Ultracold
Atomic Gases
Ultracold atoms provide a rich experimental playground for exploring fundamental quantum statistical effects. I will describe two experiments utilizing interacting ultracold bosonic atoms in optical lattices to investigate the quantum phase transition between superfluid and Mott insulator, and to simulate fractional quantum Hall effects with rotating "puddles" of small numbers of atoms. In the first experiment, high-resolution microscopy is used to directly probe the density profile of an ultracold gas of cesium-133 atoms confined to a monolayer of an optical lattice. This provides access to study both the local compressibility of an inhomogeneous gas as it crosses the SF-MI transition, as well as fluctuations in the local density. I will discuss how these measurements and the local density approximation can lead to a fairly complete measurement of the phase diagram for the bosonic Mott-insulator, normal and superfluid phases, and how careful study of fluctuations may be extended to understand quantum critical phenomena near the transition. In the second experiment, an optical lattice is used to confine small numbers of interacting rubidium-87 atoms in an array of rotating microtraps. I will describe how this system is analogous to a two-dimensional electron gas in magnetic field, and describe experiments which probe strong correlations arising from a combination of single-particle degeneracy and interparticle interactions.
Wednesday, January 27, 2010 at 12:00 PM
Room F235, Technological Institute
Refreshments are served at 11:30 PM
