Interaction-driven Spontaneous Ferromagnetic Insulating States with Odd Chern Numbers

Abstract

Motivated by recent experimental work on moiré systems in a strong magnetic field, we compute the compressibility as well as the spin correlations and Hofstadter spectrum of spinful electrons on a honeycomb lattice with Hubbard interactions using the determinantal quantum Monte Carlo method. While the interactions in general preserve quantum and anomalous Hall states, emergent features arise corresponding to an antiferromagnetic insulator at half-filling and other incompressible states following the Chern sequence $\pm (2N+1)$. These odd integer Chern states exhibit strong ferromagnetic correlations and arise spontaneously without any external mechanism for breaking the spin-rotation symmetry. Analogs of these magnetic states should be observable in general interacting quantum Hall systems. In addition, the interacting Hofstadter spectrum is qualitatively similar to the experimental data at intermediate values of the on-site interaction.

8 pages, 5 figures and a supplement

References in corpus (15)

• Quantum Hall Ferromagnetism in Graphene
• Flavour Hund's Coupling, Correlated Chern Gaps, and Diffusivity in Moiré Flat Bands
• Hofstadter subband ferromagnetism and symmetry broken Chern insulators in twisted bilayer graphene
• Hierarchy of Hofstadter states and replica quantum Hall ferromagnetism in graphene superlattices
• Fate of the false Mott-Hubbard transition in two dimensions
• Hartree-Fock study of the moiré Hubbard model for twisted bilayer transition metal dichalcogenides
• Local Order and the gapped phase of the Hubbard model: a plaquette dynamical mean field investigation
• Correlated Hofstadter Spectrum and Flavor Phase Diagram in Magic Angle Graphene
• Intertwined spin, charge and pair correlations in the two-dimensional Hubbard model in the thermodynamic limit
• Reentrant Correlated Insulators in Twisted Bilayer Graphene at 25T ($2\pi$ Flux)
• Hofstadter butterfly for a finite correlated system
• Unconventional Self-Similar Hofstadter Superconductivity from Repulsive Interactions
• Narrow bands in magnetic field and strong-coupling Hofstadter spectra
• Thermodynamics of correlated electrons in a magnetic field
• Theory of Hofstadter Superconductors

Cited by in corpus (6)

• Mapping twist-tuned multiband topology in bilayer WSe${}_2$
• Hofstadter Topology with Real Space Invariants and Reentrant Projective Symmetries
• Moiré Fractional Chern Insulators III: Hartree-Fock Phase Diagram, Magic Angle Regime for Chern Insulator States, the Role of the Moiré Potential and Goldstone Gaps in Rhombohedral Graphene Superlattices
• Exploring Ground States of Fermi-Hubbard Model on Honeycomb Lattices with Counterdiabaticity
• Incipient quantum spin Hall insulator under strong correlations
• Artificial electrostatic crystals: a new platform for creating correlated quantum states