2011/04/30 by Xiaopeng Li, Erhai Zhao, W. Vincent Liu · 1 citation
Physics and Astronomy · #Boson #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Critical point (mathematics) #Gapless playback #Hubbard model #Metal–insulator transition #Mott insulator #Mott transition #Phase transition #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Quantum, superfluid, helium dynamics #Superconductivity #Superfluidity #cond-mat.quant-gas
paper · pdf · doi:10.1103/physreva.83.063626
published as Phys. Rev. A 83, 063626 (2011) · 9+epsilon pages, 7 figures, one appendix added, accepted by Phys. Rev. A
arxiv created 2011/05/31 · openalex publication_date 2011/06/20 · arxiv updated 2015/03/18 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Motivated by the recent experiment on p-orbital-band bosons in optical lattices, we study theoretically the quantum phases of Mott insulator and superfluidity in two dimensions. The system features a superfluid phase with transversely staggered orbital current at weak interaction and a Mott insulator phase with antiferro-orbital order at strong coupling and commensurate filling. We go beyond mean-field theory and derive from a microscopic model an effective action that is capable of describing both the p-band Mott insulating and superfluid phases in strong coupling. We further calculate the excitation spectra near the quantum critical point and find two gapless modes away from the tip of the Mott lobe but four gapless modes at the tip. Our effective theory reveals how the phase coherence peak builds up in the Mott regime when approaching the critical point. We also discuss the finite-temperature phase transition of p-band superfluidity.