Mott transition with Holographic Spectral function

TL;DR

This paper demonstrates a holographic model that captures the Mott transition, showing phases like gapless, pseudo-gap, and gapped, and compares well with DMFT results and experimental data for Vanadium Oxide.

Contribution

It introduces a holographic fermion model with bulk mass and dipole interaction to realize the Mott transition, linking holography with condensed matter phenomena.

Findings

The phase diagram includes multiple phases with distinct spectral features.

The holographic spectral functions show similarities to DMFT results despite differences.

The model fits X-ray absorption data well and can fit PES data with spectral symmetrization.

Abstract

We show that the Mott transition can be realized in a holographic model of a fermion with bulk mass, $m$, and a dipole interaction of coupling strength $p$. The phase diagram contains gapless, pseudo-gap and gapped phases and the first one can be further divided into four sub-classes. We compare the spectral densities of our holographic model with the Dynamical Mean Field Theory (DMFT) results for Hubbard model as well as the experimental data of Vanadium Oxide materials. Interestingly, single-site and cluster DMFT results of Hubbard model share some similarities with the holographic model of different parameters, although the spectral functions are quite different due to the asymmetry in the holography part. The theory can fit the X-ray absorption spectrum (XAS) data quite well, but once the theory parameters are fixed with the former it can fit the photoelectric emission spectrum (PES) data only if we symmetrize the spectral function.