Phase diagram of the frustrated Hubbard model

TL;DR

This paper investigates the phase diagram of the frustrated Hubbard model, revealing that the Mott-Hubbard transition is concealed within an antiferromagnetic insulator even under strong magnetic frustration, challenging its role in the model's generic phase diagram.

Contribution

It demonstrates that the Mott-Hubbard transition is hidden inside a robust antiferromagnetic insulator despite magnetic frustration.

Findings

The Mott-Hubbard transition is concealed within an antiferromagnetic insulator.

Magnetic frustration does not eliminate the insulating phase.

The relevance of the Mott-Hubbard transition in the phase diagram is questioned.

Abstract

The Mott-Hubbard metal-insulator transition in the paramagnetic phase of the one-band Hubbard model has long been used to describe similar features in real materials like V$_2$O$_3$. Here we show that this transition is hidden inside a rather robust antiferromagnetic insulator even in the presence of comparatively strong magnetic frustration. This result raises the question of the relevance of the Mott-Hubbard metal-insulator transition for the generic phase diagram of the one-band Hubbard model.