Mott Transition and Strange Metal in Two Dimensions: A View from Cellular Dynamical Cluster Approximation

TL;DR

This paper introduces a Cellular Dynamical Cluster Approximation to study the Mott transition in a 2D extended Hubbard model, revealing a non-Fermi liquid phase driven by strong correlations and providing insights into the strange metal behavior in cuprates.

Contribution

It presents a novel CDCA method to analyze the 2D Mott transition, demonstrating a non-Fermi liquid phase caused by Anderson orthogonality, linking theoretical predictions to experimental strange metal phenomena.

Findings

Identification of a d-wave Mott insulator at strong coupling.

Observation of a first-order Mott transition to a non-Fermi liquid metal upon doping.

Explanation of strange metal behavior via Anderson orthogonality in 2D.

Abstract

We introduce a Cellular Dynamical Cluster Approximation (CDCA) to study the nature of the Mott insulator-metal transition in the extended Hubbard model on a square lattice. At strong coupling, a d-wave Mott insulator is obtained. Hole doping drives a first order Mott transition to a non-Fermi (nFL) liquid metal. Remarkably, this nFL is caused by an Anderson orthogonality catastrophe at low energies due to the non-trivial competition between strong, non-local interactions and hopping. This constitutes the first explicit realisation of Anderson's Luttinger liquid idea in two dimensions. Many experimental responses in the ``strange metal'' phase found around optimal doping in cuprates are understood naturally within our approach.