RT Journal Article
SR Electronic
T1 Observation of Quantum Criticality with Ultracold Atoms in Optical Lattices
JF Science
JO Science
FD American Association for the Advancement of Science
SP 1070
OP 1072
DO 10.1126/science.1217990
VO 335
IS 6072
A1 Zhang, Xibo
A1 Hung, Chen-Lung
A1 Tung, Shih-Kuang
A1 Chin, Cheng
YR 2012
UL http://science.sciencemag.org/content/335/6072/1070.abstract
AB Quantum criticality emerges when a many-body system is in the proximity of a continuous phase transition that is driven by quantum fluctuations. In the quantum critical regime, exotic, yet universal properties are anticipated; ultracold atoms provide a clean system to test these predictions. We report the observation of quantum criticality with two-dimensional Bose gases in optical lattices. On the basis of in situ density measurements, we observe scaling behavior of the equation of state at low temperatures, locate the quantum critical point, and constrain the critical exponents. We observe a finite critical entropy per particle that carries a weak dependence on the atomic interaction strength. Our experiment provides a prototypical method to study quantum criticality with ultracold atoms.