Phases of a 2D Bose Gas in an Optical Lattice

Abstract

Ultra-cold atoms in optical lattices realize simple, fundamental models in condensed matter physics. Our 87Rb Bose-Einstein condensate is confined in a harmonic trapping potential to which we add an optical lattice potential. Here we realize the 2D Bose-Hubbard Hamiltonian and focus on the effects of the harmonic trap, not present in bulk condensed matter systems. By measuring condensate fraction we identify the transition from superfluid to Mott insulator as a function of atom density and lattice depth. Our results are in excellent agreement with the quantum Monte Carlo universal state diagram, suitable for trapped systems, introduced by Rigol et al. (Phys. Rev. A 79, 053605 (2009)).

5 pages, 4 figures

References in corpus (5)

• Imaging the Mott Insulator Shells using Atomic Clock Shifts
• Quantum Monte Carlo simulations of confined bosonic atoms in optical lattices
• Formation of spatial shell structures in the superfluid to Mott insulator transition
• Phase diagram for a Bose-Einstein condensate moving in an optical lattice
• Condensate fraction in a 2D Bose gas measured across the Mott-insulator transition

Cited by in corpus (9)

• Cooling in strongly correlated optical lattices: prospects and challenges
• Superfluid to normal phase transition in strongly correlated bosons in two and three dimensions
• Bogoliubov theory of interacting bosons on a lattice in a synthetic magnetic field
• Quantum Criticality from in-situ Density Imaging
• Effect of particle statistics in strongly correlated two-dimensional Hubbard models
• Controlling coherence via tuning of the population imbalance in a bipartite optical lattice
• Oscillatory pairing of fermions in spin-split traps
• Scaling behaviour of trapped bosonic particles in two dimensions at finite temperature
• Excitation Spectra and Hard-core Thermodynamics of Bosonic Atoms In Double Well Optical Lattices