Dynamic Mott gap from holographic fermions in geometries with hyperscaling violation

TL;DR

This paper explores how holographic fermions in geometries with hyperscaling violation can dynamically generate a Mott gap, revealing the effects of dipole coupling strength on spectral functions and band structures.

Contribution

It introduces a study of Mott gap formation via holography in hyperscaling violating geometries using bulk dipole coupling, highlighting the impact on spectral features and band behavior.

Findings

A stable Mott gap and two bands emerge beyond a critical coupling.

The upper band is sharper and on the positive frequency side.

Increasing hyperscaling violation smooths out the bands.

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.