  We, based on the photoassociation of fermion atoms into bosonic molecules,
propose a scheme to create the steady entanglement between the atom state and
the molecule state inside an optical lattice. The stability of entanglement
state is guaranteed by sweeping the frequency of Ramman laser beam through
resonance according to the second Demkov-Kunike (DK2) nonadiabatic transition
model\cite{DK,models}. The probability amplitude of each components can be
precisely controlled by adjusting the sweeping parameter.
