  Rotation of atoms in a lattice is studied using a Hubbard model. It is found
that the atoms are still contained in the trap even when the rotation frequency
is larger than the trapping frequency. This is very different from the behavior
in continuum. Bragg scattering and coupling between angular and radial motion
are believed to make this stability possible. In this regime, density depletion
at the center of the trap can be developed for spin polarized fermions.
