I continue to be amazed at such optical lattice experiments. The ability to trap atoms in lasers and have each atom placed in an optical lattice is such an amazing accomplishment. It opens the door to performing so many studies on strongly correlated systems since the strength of the individual coupling can be tuned via the optical lattice separation.
A new experiment using such technique has appeared in Science this week.
W.S. Bakr et al., Science v.329, p.547 (2010).
Abstract: Quantum gases in optical lattices offer an opportunity to experimentally realize and explore condensed matter models in a clean, tunable system. We used single atom–single lattice site imaging to investigate the Bose-Hubbard model on a microscopic level. Our technique enables space- and time-resolved characterization of the number statistics across the superfluid–Mott insulator quantum phase transition. Site-resolved probing of fluctuations provides us with a sensitive local thermometer, allows us to identify microscopic heterostructures of low-entropy Mott domains, and enables us to measure local quantum dynamics, revealing surprisingly fast transition time scales. Our results may serve as a benchmark for theoretical studies of quantum dynamics, and may guide the engineering of low-entropy phases in a lattice.
Read the Perspective on this work in the same issue of Science.