Volume 104, Number 1, October 2013
|Number of page(s)||6|
|Section||Condensed Matter: Structural, Mechanical and Thermal Properties|
|Published online||25 October 2013|
Quantum XY criticality in a two-dimensional Bose gas near the Mott transition
1 James Franck Institute and Department of Physics, University of Chicago - Chicago, IL 60637, USA
2 Laboratoire de Physique Théorique de la Matière Condensée, CNRS UMR 7600, Université Pierre et Marie Curie 4 Place Jussieu, 75252 Paris Cedex 05, France
Received: 12 July 2013
Accepted: 1 October 2013
We derive the equation of state of a two-dimensional Bose gas in an optical lattice in the framework of the Bose-Hubbard model. We focus on the vicinity of the multicritical points where the quantum phase transition between the Mott insulator and the superfluid phase occurs at fixed density and belongs to the three-dimensional XY model universality class. Using a nonperturbative renormalization-group approach, we compute the pressure P(μ, T) as a function of chemical potential and temperature. Our results compare favorably with a calculation based on the quantum O(2) model —we find the same universal scaling function— and allow us to determine the region of the phase diagram in the vicinity of a quantum multicritical point where the equation of state is universal. We also discuss the possible experimental observation of quantum XY criticality in an ultracold gas in an optical lattice.
PACS: 67.85.-d – Ultracold gases, trapped gases / 05.30.Rt – Quantum phase transitions / 05.30.Jp – Boson systems
© EPLA, 2013
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.