Magnetic phase diagram and Mott transition of the half-filled 1/5-depleted Hubbard model with frustration

TL;DR

This study investigates the magnetic phases and Mott transition in a half-filled, frustrated Hubbard model on a 1/5 depleted square lattice, revealing how frustration suppresses magnetic order and induces a non-magnetic Mott transition.

Contribution

It provides a detailed phase diagram showing the effects of frustration on magnetic order and Mott transition in the 1/5 depleted Hubbard model using the variational cluster approximation.

Findings

Néel order dominates in unfrustrated cases

Frustration suppresses magnetic order

Non-magnetic Mott transition occurs with moderate frustration

Abstract

The magnetic properties and Mott transition of the half-filled Hubbard model on the 1/5 depleted square lattice with frustration is studied at zero temperature by the variational cluster approximation. The $(\pi,\pi)$ N\'eel ordering (AF) is stable in a wide region of the phase diagram and almost completely veils the non-magnetic Mott transition for the unfrustrated case. However, AF is severely suppressed by the frustration and even with moderate frustrations the non-magnetic Mott transition takes place in the range where the intra-dimer hoppings are larger than the intra-plaquette hoppings.