3D Anderson Localization of Ultracold Matter

Anderson localization (AL) is a ubiquitous interference phenomenon in which waves fail to propagate in a disordered medium.  We observe three-dimensional AL of non-interacting ultracold matter by allowing a spin-polarized atomic Fermi gas to expand into a disordered potential that is creating using optical speckle.  A two-component density distribution emerges consisting of an expanding mobile component and a non-diffusing localized component. We extract a mobility edge that increases with the disorder strength, whereas the thermally averaged localization length is shown to decrease with disorder strength and increase with particle energy. Progress toward combining disordered fermions with an optical lattice in order to realize the disordered (Fermi-) Hubbard model will be discussed.