  We illustrate how a completely new world of gauge force emerges from a
conventional condensed matter system in a rigorous way. A characteristic energy
scale (Mott gap) separates such an exotic universe from the ordinary one that
we condensed matter physicists are more familiar with at higher energies. The
governing physical law is no longer about individual electrons but concerns
fractionalized particles, i.e., partons, as the new collective modes resulted
from strong correlation among the electrons. Novel phenomena in this low-energy
universe are clearly distinguished from Landau's Fermi liquid described by the
perturbative quantum many-body theory.
