Long range magnetic ordering of ultracold fermions in an optical lattice

We present progress towards the observation of long range antiferromagnetic (AFM) ordering of fermionic $^{6}$Li atoms in an optical lattice. We prepare a two spin state mixture of $10^{6}$ atoms at $T/T_{F}=0.1$ by evaporatively cooling in an optical dipole trap. The sample is then transferred to a dimple trap formed by three retroreflected laser beams at 1064~nm that propagate in orthogonal directions. The polarization of the retroreflected light is controlled using liquid crystal retarders, which allow us to adiabatically transform the dimple trap into a 3D lattice. Overlapped with each of the three dimple/lattice beams is a beam at 532~nm, which can cancel the harmonic confinement and flatten the band structure in the lattice. This setup offers the possibility of implementing proposed schemes\footnote{C. J. M. Mathy et al., Phys. Rev. A \textbf{86}, 023606 (2011)} which enlarge the size of the AFM phase in the trap. As a probe for AFM we use Bragg scattering of light\footnote{T. A. Corcovilos et al., Phys. Rev. A \textbf{81}, 013415 (2010)}. We have observed Bragg scattering off of the (100) lattice planes, and using an off-angle probe we can see the diffuse scattering from the sample which serves as background for the small signals expected before the onset of AFM ordering.