2:45-3:15pm, Tea, Coffee, and Cookie

We prepare and study strongly interacting two-dimensional Bose gases
with dimensionless gas parameter as high as g=2.8 by Feshbach tuning and
by loading the sample into an optical lattice. In the superfluid and BKT
transition regimes, significant down-shifts from the mean-field and
perturbation calculations are observed when g approaches or exceeds one.
In the BKT and the quantum critical regimes, all measured thermodynamic
quantities show logarithmic dependence on the interaction strength.

We also outline a prototypical approach to investigate quantum transport
phenomena and quantum quenches. Starting with an almost pure bosonic
superfluid, we quench the particle interactions and observe an
oscillating density fluctuation in the time and momentum domains.These
so called Sakharov oscillations, typically discussed in the
context of early universe evolution, provide a common basis to
understand the quantum quench dynamics of atomic superfluid and the
anisotropy of the cosmic microwave background radiation.