Two- and three-dimensional strong localization of matter waves by atomic scatterers
Résumé
We study the strong localization of atomic matter waves in a disordered potential created by atoms pinned
at the nodes of a lattice, for both three-dimensional (3D) and two-dimensional (2D) systems. The localization
length of the matter wave, the density of localized states, and the occurrence of energy mobility edges (for the 3D
system), are numerically investigated as a function of the effective scattering length between the atomic matter
wave and the pinned atoms. Both positive and negative matter wave energies are explored. Interesting features
of the density of states are discovered at negative energies, where maxima in the density of bound states for the
system can be interpreted in terms of bound states of a matter wave atom with a few pinned atomic scatterers.
In 3D we found evidence of up to three mobility edges, one at positive energies, and two at negative energies,
the latter corresponding to transitions between extended and localized bound states. In 2D, no mobility edge is
found, and a rapid exponential-like increase of the localization length is observed at high energy.