Abstract
We investigate the localization properties of atoms moving in a three-dimensional optical lattice in the presence of a disorder potential having the same probability distribution as laser speckles, and a spatial correlation length much shorter than the lattice spacing. We find that the disorder-averaged (single-particle) Green's function, calculated via the coherent-potential approximation, is in very good agreement with exact numerics. Using the transfer-matrix method, we compute the phase diagram in the energy-disorder plane and show that its peculiar shape can be understood from the self-consistent theory of localization. In particular, we recover the large asymmetry in the position of the mobility edge for blue and red speckles, which was recently observed numerically for spatially correlated speckle potentials.
- Received 19 September 2015
DOI:https://doi.org/10.1103/PhysRevA.92.053618
©2015 American Physical Society