Antiferromagnetism with Ultracold Atoms
Ultracold atoms on optical lattices form a versatile platform for studying many-body physics, with the potential of addressing some of the most important issues in strongly correlated matter. Progress, however, has been stymied by an inability to create sufficiently low temperatures in an optical lattice. In this talk, I will present our experimental results on the characterization of the three-dimensional Hubbard model near half-filling, realized using two spin-states of fermionic atomic lithium (6Li). We have developed a compensated optical lattice that has enabled, for the first time, the achievement of temperatures that are below the tunneling energy in the lattice, t. For strong interactions, we observe the emergence of a density plateau and a reduction of the compressibility, indicative of the formation of a Mott insulator. The Hubbard model is known to exhibit antiferromagnetism at temperatures below the Néel temperature TN. We have detected antiferromagnetic correlations by spin-sensitive Bragg scattering of light.