Filling-driven Mott transition in SU(N) Hubbard models

TL;DR

This paper investigates the filling-driven Mott transition in SU(N) Hubbard models, revealing temperature-dependent compressibility behavior linked to quasiparticle spectral features using DMFT and NRG.

Contribution

It introduces a detailed analysis of the filling-driven Mott transition in SU(N) models, highlighting the role of temperature and spectral asymmetry with advanced numerical methods.

Findings

Compressibility is strongly enhanced near the critical temperature.

Thermal suppression of the quasiparticle peak explains the compressibility behavior.

Asymmetry in the quasiparticle peak stems from doublon-holon dynamics.

Abstract

We study the filling-driven Mott transition involving the metallic and paramagnetic insulating phases in SU(N) Fermi-Hubbard models, using dynamical mean-field theory (DMFT) and the numerical renormalization group (NRG) as impurity solver. The compressibility shows a striking temperature dependence: near the critical temperature, it is strongly enhanced in the metallic phase close to the insulating phase. We demonstrate that this compressibility enhancement is associated with the thermal suppression of the quasiparticle peak in the local spectral functions. We also explain that the asymmetric shape of the quasiparticle peak originates from the asymmetry in the underlying doublon-holon dynamics.