When an ultracold spinor atomic gas (Bosonic or
Fermionic) is loaded into an optical lattice, spin-dependent
virtual tunneling can be induced between neighboring atoms by
varying the potential depth in a spin-dependent way. This provides us
a powerful technique to engineer many-body Hamiltonians. We show
that in the strong interaction region, by this technique, we can
realize various kinds of strongly-correlated spin Hamiltonians,
which either have rich phase diagrams under change of some tunable
parameters, or support exotic abelian and non-abelian anyonic
excitations, or provide a simplified way to implement scalable
quantum computation.