Dimensional-crossover-driven Mott transition in the frustrated Hubbard model

TL;DR

This paper investigates how dimensional crossover influences the Mott transition in a frustrated Hubbard model, revealing a metallic phase with Fermi surface pockets and enhanced pairing correlations driven by frustration and dimensionality effects.

Contribution

It demonstrates the continuous transition from one to two dimensions in a frustrated Hubbard model using cluster dynamical mean-field theory, highlighting the emergence of a pseudogap phase with Fermi pockets.

Findings

Fermi surface pockets emerge due to remnant one-dimensional Umklapp scattering.

A pseudogap phase with enhanced d-wave pairing correlations is observed.

The transition from 1D to 2D is continuous within the studied parameters.

Abstract

We study the Mott transition in a frustrated Hubbard model with next-nearest neighbor hopping at half-filling. The interplay between interaction, dimensionality and geometric frustration closes the one-dimensional Mott gap and gives rise to a metallic phase with Fermi surface pockets. We argue that they emerge as a consequence of remnant one-dimensional Umklapp scattering at the momenta with vanishing interchain hopping matrix elements. In this pseudogap phase, enhanced d-wave pairing correlations are driven by antiferromagnetic fluctuations. Within the adopted cluster dynamical mean-field theory on the $8\times 2$ cluster and down to our lowest temperatures the transition from one to two dimensions is continuous.