Quantum critical behavior of ultracold atoms in two-dimensional optical lattices

Details Quantum critical behavior of ultracold atoms in two-dimensional optical lattices Quantum critical behavior of ultracold atoms in two-dimensional optical lattices

2011-09-02

arxiv.org/abs/1109.0344v1

Science 335, 1070 (2012)

Physics

Condensed Matter

Quantum Gases

7 pages, 4 figures

Scientific paper

10.1126/science.1217990

As the temperature of a many-body system approaches absolute zero, thermal fluctuations of observables cease and quantum fluctuations dominate. Competition between different energies, such as kinetic energy, interactions or thermodynamic potentials, can induce a quantum phase transition between distinct ground states. Near a continuous quantum phase transition, the many-body system is quantum critical, exhibiting scale invariant and universal collective behavior \cite{Coleman05Nat, Sachdev99QPT}. Quantum criticality has been actively pursued in the study of a broad range of novel materials \cite{vdMarel03Nat, Lohneysen07rmp, G08NatPhys, Sachdev08NatPhys}, and can invoke new insights beyond the Landau-Ginzburg-Wilson paradigm of critical phenomena \cite{Senthil04prb}. It remains a challenging task, however, to directly and quantitatively verify predictions of quantum criticality in a clean and controlled system. Here we report the observation of quantum critical behavior in a two-dimensional Bose gas in optical lattices near the vacuum-to-superfluid quantum phase transition. Based on \textit{in situ} density measurements, we observe universal scaling of the equation of state at sufficiently low temperatures, locate the quantum critical point, and determine the critical exponents. The universal scaling laws also allow determination of thermodynamic observables. In particular, we observe a finite entropy per particle in the critical regime, which only weakly depends on the atomic interaction. Our experiment provides a prototypical method to study quantum criticality with ultracold atoms, and prepares the essential tools for further study on quantum critical dynamics.

Affiliated with

Also associated with

No associations

Rating

Quantum critical behavior of ultracold atoms in two-dimensional optical lattices does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Quantum critical behavior of ultracold atoms in two-dimensional optical lattices, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Quantum critical behavior of ultracold atoms in two-dimensional optical lattices will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-687326