Mott transition and ferrimagnetism in the Hubbard model on the anisotropic kagom\'e lattice

TL;DR

This paper investigates the Mott transition and ferrimagnetism in the Hubbard model on an anisotropic kagomé lattice, revealing how geometric frustration influences magnetic phases and heavy fermion behavior at zero temperature.

Contribution

It provides a detailed phase diagram showing the interplay of frustration, electron correlations, and magnetic order in the Hubbard model on an anisotropic kagomé lattice.

Findings

Ferrimagnetic phase expands as geometric frustration decreases.

Mott insulator phase vanishes in moderately frustrated regions.

Heavy fermion behavior with mass enhancement observed in metallic phase.

Abstract

Mott transition and ferrimagnetism are studied in the Hubbard model on the anisotropic kagom\'e lattice using the variational cluster approximation and the phase diagram at zero temperature and half-filling is analyzed. The ferrimagnetic phase rapidly grows as the geometric frustration is relaxed, and the Mott insulator phase disappears in moderately frustrated region, showing that the ferrimagnetic fluctuations stemming from the relaxation of the geometric frustration is enhanced by the electron correlations. In metallic phase, heavy fermion behavior is observed and mass enhancement factor is computed. Enhancement of effective spatial anisotropy by the electron correlations is also confirmed in moderately frustrated region, and its effect on heavy fermion behavior is examined.