Slow mass transport and statistical evolution of an atomic gas across the superfluid-Mott-insulator transition.
We study transport dynamics of ultracold cesium atoms in a two-dimensional optical lattice across the superfluid-Mott-insulator transition based on in situ imaging. Inducing the phase transition with a lattice ramping routine expected to be locally adiabatic, we observe a global mass redistribution which requires a very long time to equilibrate, more than 100 times longer than the microscopic time scales for on-site interaction and tunneling. When the sample enters the Mott-insulator regime, mass transport significantly slows down. By employing fast recombination loss pulses to analyze the occupancy distribution, we observe similarly slow-evolving dynamics, and a lower effective temperature at the center of the sample.
Hung
Chen-Lung
CL
The James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637, USA.
Zhang
Xibo
X
Gemelke
Nathan
N
Chin
Cheng
C