Mott transition in Kagom\'e lattice Hubbard model

TL;DR

This study explores the Mott transition in the Kagomé lattice Hubbard model, revealing a first-order transition at a specific interaction strength and uncovering heavy quasiparticles and anomalous spin behavior near the transition.

Contribution

It provides the first detailed analysis of the Mott transition in the Kagomé lattice Hubbard model using cluster dynamical mean field theory, highlighting the formation of heavy quasiparticles and frustration effects.

Findings

First-order Mott transition at U/W ~ 1.4

Strong renormalization of three bands near transition

Anomalous temperature dependence of spin correlations

Abstract

We investigate the Mott transition in the Kagom\'e lattice Hubbard model using a cluster extension of dynamical mean field theory. The calculation of the double occupancy, the density of states, the static and dynamical spin correlation functions demonstrates that the system undergoes the first-order Mott transition at the Hubbard interaction $U/W \sim 1.4$ ($W$:bandwidth). In the metallic phase close to the Mott transition, we find the strong renormalization of three distinct bands, giving rise to the formation of heavy quasiparticles with strong frustration. It is elucidated that the quasiparticle states exhibit anomalous behavior in the temperature-dependent spin correlation functions.