  The general equivalence principle and the associated diffeomorphism gauge
symmetry are regarded as a founding principles of nature. But, one may wonder,
can diffeomorphism gauge symmetry emerge as a low energy property of certain
topological/quantum order in a qbit model that has no diffeomorphism gauge
symmetry? In this paper, we showed that, at least, the linearized
diffeomorphism gauge symmetry h_{\mu\nu}\to h_{\mu\nu} +\prt_\mu f_\nu+\prt_\nu
f_\mu can indeed emerge from some qbit models (or quantum spin models).
Physically, the emergence of the (linearized) diffeomorphism gauge symmetry
implies the emergence of gapless helicity +/- 2 excitations (ie the gravitons).
  In the first qbit model (called the L-type model), we show that helicity +/-
2 gapless excitations appear as the only type of low energy excitations using a
reliable semiclassical approach. The dispersion of the gapless helicity +/- 2
is found to be \eps_k \propto k^3. The appearance of the gapless helicity +/- 2
modes suggests that the ground state of the qbit model is a new state of
matter. In the second model (called the N-type model) the collective modes are
strongly interacting and there is no reliable approach to understand its low
energy dynamics. Using a spin-wave/quantum-freeze approach (which is shown to
reproduce the correct emergent U(1) gauge theory in a quantum rotor model), we
argue that the second model may contain helicity +/- 2 gapless excitations as
the only type of low energy excitations with a linear dispersion \om \propto k.
