Non-adiabatic loading of a Bose-Einstein condensate into the ground state of an optical lattice

We present a scheme for rapid loading of a Bose-Einstein condensate into a single Bloch state of a weak optical lattice at a quasi-momentum of q = hbar k. Rabi cycling of a Bose condensate between momentum states is modified by a phase shift applied to the lattice. With an appropriate choice of the magnitude and timing of the phase shift, we demonstrate nearly perfect loading of the lattice ground state, the signature of which is an abrupt halt to the Rabi cycling.