  We construct a holographic model for a fermionic system on Q-lattice and
compute the spectral function in the presence of a dipole coupling. Both key
features of doped Mott insulators, the dynamical generation of a gap and
spectral weight transfer, are observed when adjusting the value of the coupling
parameter $p$. Of particular interest is that when the background is in a deep
insulating phase, the Mott gap opens much easier with a smaller coupling
parameter in comparison with a metallic background. The effects of lattice
parameters on the width of the gap $\Delta/\mu$ are studied and a turning point
is observed near the critical regime of metal-insulator transitions of the
background. Furthermore, the temperature dependence of the spectral function is
studied. Finally, we also observe that the anisotropic Q-lattice generates
anisotropic peaks with different magnitudes, indicating that insulating and
metallic phases arise in different directions.
