The Mott Insulator Transition in a Two Dimensional Atomic Bose Gas
Ian B. Spielman, William D. Phillips, James V. Porto
Cold atoms confined in periodic potentials are remarkably versatile quantum systems for implementing simple models prevalent in condensed matter theory. Here we realize the 2D Bose-Hubbard model by loading a Bose-Einstein condensate into an optical lattice, and we study the resulting Mott insulating state (a phase of matter in which atoms are localized on specific lattice sites). Wemeasure momentum distributions which agree quantitatively with theory (no adjustable parameters). We also study correlations in atom shot nose and observe a marked dependence on the lattice depth, as expected from simple arguments.