Dimensional and temperature dependence of metal insulator transition in correlated and disordered systems

TL;DR

This paper investigates how dimensionality, temperature, and disorder influence the metal-insulator transition in a 2D correlated disordered Hubbard model, revealing complex phase behaviors and the effects of Fibonacci sequence disorder.

Contribution

It introduces a study of the interplay between correlation and deterministic Fibonacci disorder in 2D systems, highlighting dimensional effects on phase transitions.

Findings

Disorder induces metallic phases at certain interaction strengths.

Correlation favors antiferromagnetic order above a critical U.

Dimensional crossover affects electronic and magnetic properties.

Abstract

We study the dimensional dependence of the interplay between correlation and disorder in two dimension at half filling using 2D $t-t'$ disordered Hubbard model with deterministic disorder both at zero and finite temperatures. Inclusion of $t'$ without disorder leads to a metallic phase at half filling below a certain critical value of $U$. Above this critical value $U_c$ correlation favours antiferromagnetic phase. Since disorder leads to double occupancy over the lower energy site, the competition between Hubbard $U$ and disorder leads to the emergence of a metallic phase, which can be quantified by the calculation of Kubo conductivity, gap at half-filling, density of states, spin order parameter, Inverse participation ratio (IPR) and bandwidth. We have studied the effect of disorder on the system in a very novel way through a deterministic disorder which follows a Fibonacci sequence. Behaviour of different parameters show interesting features on going from a two to quasi one dimensional system.