2015/06/30 by Jiao Miao · 4 citations
Physics and Astronomy · #Amplitude #Bose–Hubbard model #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Hubbard model #Lattice (music) #Mott insulator #Optical lattice #Phase (matter) #Phase diagram #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Quantum, superfluid, helium dynamics #Superconductivity #Superfluidity #Tricritical point #cond-mat.quant-gas
paper · pdf · doi:10.1103/physreva.92.023632
published in Physical Review A 92(2) (American Physical Society) · 6 pages, 6 figures
openalex publication_date 2015/08/24 · arxiv created 2015/09/03 · arxiv updated 2015/09/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study an extended Bose-Hubbard model with next-nearest-neighbor (NNN) hopping in a shaken optical lattice. We show how mean-field phase diagram evolves with the change of NNN hopping amplitude t2, which can be easily tuned via shaking amplitude. As t2 increases, a Z2-symmetry-breaking superfluid (Z2SF) phase emerges at the bottom of the Mott lobs. The tricritical points between normal superfluid, Z2SF, and Mott insulator (MI) phases are identified. We further demonstrate the tricritical point can be tuned to the tip of the Mott lobe, in which case a new critical behavior has been predicted. Within random-phase approximation, excitation spectra in the three phases are obtained, which indicate how the phase transitions occur.