2002/09/03 by R. Roth, Robert Roth, K. Burnett · 125 citations
Physics and Astronomy · #Atomic and Subatomic Physics Research #Bose–Hubbard model #Boson #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Hubbard model #Interference (communication) #Lattice (music) #Mott insulator #Observable #Optical lattice #Phase transition #Physics #Quantum #Quantum mechanics #Quantum, superfluid, helium dynamics #Superconductivity #Superfluidity #Ultracold atom #cond-mat.stat-mech #physics.atom-ph
paper · pdf · doi:10.1103/physreva.67.031602
published in Physical Review A 67(3) (American Physical Society) · 4 pages, 3 figures, using REVTEX4
arxiv created 2002/09/03 · openalex publication_date 2003/03/25 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present a study of the superfluid properties of atomic Bose gases in optical lattice potentials using the Bose-Hubbard model. To do this, we use a microscopic definition of the superfluid fraction based on the response of the system to a phase variation imposed by means of twisted boundary conditions. We compare the superfluid fraction to other physical quantities, i.e., the interference pattern after ballistic expansion, the quasimomentum distribution, and number fluctuations. We have performed exact numerical calculations of all these quantities for small one-dimensional systems. We show that the superfluid fraction alone exhibits a clear signature of the Mott-insulator transition. Observables like the fringe visibility, which probe only ground-state properties, do not provide direct information on superfluidity and the Mott-insulator transition.