Finite-Temperature Ferromagnetic Correlations of the Kagome Lattice Hubbard Model

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Correia, Francisco, Corbett, Kyle, Khatami, Ehsan
Natura: Preprint
Pubblicazione: 2026
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866917447575011328
author Correia, Francisco
Corbett, Kyle
Khatami, Ehsan
author_facet Correia, Francisco
Corbett, Kyle
Khatami, Ehsan
contents The Kagome lattice Fermi-Hubbard model is one of the most physically rich, and at the same time most challenging, models to study in strongly-correlated physics. Among its special features are geometric frustration and a flat energy band that create conditions favorable to ferromagnetism near the band insulating limit. Here, we utilize two exact finite-temperature methods, the numerical linked-cluster expansion and the determinant quantum Monte Carlo, to study the extent as well as doping and interaction dependence of ferromagnetic correlations and other thermodynamic properties of the model. We find that repulsive interactions enhance ferromagnetic correlations at high electron densities and that increasing the interaction strength, extends the region with strong ferromagnetic correlations towards half filling, smoothly connecting it to Nagaoka ferromagnetism near the Mott insulating region. We also use the charge compressibility to obtain an accurate estimate for the critical interaction strength for the metal-insulator transition at half filling. These results improve our understanding of the magnetic tendencies of the model away from half filling and pave the way for further studies, including with ultracold atoms in optical lattices.
format Preprint
id arxiv_https___arxiv_org_abs_2604_26827
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Finite-Temperature Ferromagnetic Correlations of the Kagome Lattice Hubbard Model
Correia, Francisco
Corbett, Kyle
Khatami, Ehsan
Strongly Correlated Electrons
The Kagome lattice Fermi-Hubbard model is one of the most physically rich, and at the same time most challenging, models to study in strongly-correlated physics. Among its special features are geometric frustration and a flat energy band that create conditions favorable to ferromagnetism near the band insulating limit. Here, we utilize two exact finite-temperature methods, the numerical linked-cluster expansion and the determinant quantum Monte Carlo, to study the extent as well as doping and interaction dependence of ferromagnetic correlations and other thermodynamic properties of the model. We find that repulsive interactions enhance ferromagnetic correlations at high electron densities and that increasing the interaction strength, extends the region with strong ferromagnetic correlations towards half filling, smoothly connecting it to Nagaoka ferromagnetism near the Mott insulating region. We also use the charge compressibility to obtain an accurate estimate for the critical interaction strength for the metal-insulator transition at half filling. These results improve our understanding of the magnetic tendencies of the model away from half filling and pave the way for further studies, including with ultracold atoms in optical lattices.
title Finite-Temperature Ferromagnetic Correlations of the Kagome Lattice Hubbard Model
topic Strongly Correlated Electrons
url https://arxiv.org/abs/2604.26827