Dynamic Mott gap from holographic fermions in geometries with hyperscaling violation

We investigate a dynamically generated Mott gap from holographic fermions in asymptotical geometries with hyperscaling violation by employing a bulk dipole coupling for fermions. We find that when the coupling strength increases, the spectral function first appears at the negative frequency region but is soon transferred to the positive region. A stable gap and two bands emerge for all momentums when the coupling strength exceeds a critical value. Generally, the upper band on the positive frequency axis is much sharper than the lower band on the negative side. When the diploe coupling increases further, the gap becomes larger. The upper band keeps sharp while the lower band disperses and widens, concentrating on the small momentum space. We also find that the bands will be smoothed out gradually with the increasing of hyperscaling violation.