Dynamic Mott gap from holographic fermions in geometries with hyperscaling violation

Abstract

We investigate a dynamically generated Mott gap from holographic fermions in asymptotically geometries with hyperscaling violation by employing a bulk dipole coupling for the fermion field. We find that when the coupling strength increases the spectral function first transfers to the negative frequency region but soon redistributes to the positive region. A stable gap and two bands emerges for all momentum when the coupling strength beyonds 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 and the up band still keeps sharp while the lower band disperses and widens, concentrating on the small momentum region. We also find that the bands will be smoothed out gradually with the increasing of hyperscaling violation.