Finite doping signatures of the Mott transition in the two-dimensional Hubbard model

TL;DR

This paper investigates how short-range spin correlations affect the Mott transition in the two-dimensional Hubbard model, revealing a first-order transition surface and a maximum scattering rate at finite doping.

Contribution

It provides a detailed phase diagram of the Hubbard model incorporating short-range correlations using cluster dynamical mean-field theory.

Findings

Identification of a first-order transition surface between two metallic phases.

Observation of a maximum in scattering rate above the critical end line.

Demonstration of the influence of doping on the Mott transition in layered materials.

Abstract

Experiments on layered materials call for a study of the influence of short-range spin correlations on the Mott transition. To this end, we solve the cluster dynamical mean-field equations for the Hubbard model on a plaquette with continuous-time quantum Monte Carlo. The normal state phase diagram as a function of temperature $T$, interaction strength $U$ and filling $n$ reveals that upon increasing $n$ towards the insulator, there is a surface of first-order transition between two metals at non-zero doping. For $T$ above the critical end line there is a maximum in scattering rate.