Geometric Frustration Assisted Kinetic Ferromagnetism in Doped Mott Insulators

Abstract

Understanding ferromagnetism mechanism in doped Mott insulators on frustrated lattices remains challenging at intermediate coupling and finite doping. Here, we study the itinerant ferromagnetism and propose its mechanism in doped Mott insulators on a geometrically frustrated triangular lattice. Using large-scale density matrix renormalization group (DMRG) and unrestricted Hartree-Fock mean-field methods, we reveal that itinerant ferromagnetism appears at intermediate coupling ($10\lesssim U\ll \infty$) near 50% electron doping in the triangular-lattice Hubbard model. By analyzing all microscopic hopping processes, we find that doublon-singlon exchange alone drives the fully polarized ferromagnetism and uncovers the particle-hole asymmetry. We also establish the magnetic phase diagram and compare local spin correlations with recent experiments. Random phase approximation and DMRG calculations consistently confirm that the ferromagnetism persists when $SU(2)$ symmetry is explicitly broken by magnetic anisotropy. These results clarify a microscopic route to itinerant ferromagnetism at intermediate coupling and finite doping in doped Mott insulators.

arXiv comment9+8 pages; 6+7 figures

References in corpus (38)

• Feshbach Resonances in Ultracold Gases
• "Deconfined" quantum critical points
• Magic continuum in twisted bilayer WSe2
• Quantum criticality beyond the Landau-Ginzburg-Wilson paradigm
• Abundance of correlated insulating states at fractional fillings of WSe${}_2$/WS${}_2$ moiré superlattices
• From Nagaoka's ferromagnetism to flat-band ferromagnetism and beyond: An introduction to ferromagnetism in the Hubbard model
• Scalar spin chirality and quantum Hall effect on a triangular lattice
• Stripe phases in WSe2/WS2 moiré superlattices
• Programming Correlated Magnetic States via Gate Controlled Moiré Geometry
• Ferromagnetism in the Hubbard Model on fcc-type lattices
• Frustration- and doping-induced magnetism in a Fermi-Hubbard simulator
• Kinetic Magnetism in Triangular Moiré Materials
• Ferromagnetism, paramagnetism and a Curie-Weiss metal in an electron doped Hubbard model on a triangular lattice
• Phases of the infinite U Hubbard model
• Non-perturbative approaches to magnetism in strongly correlated electron systems
• Site-resolved imaging of ultracold fermions in a triangular-lattice quantum gas microscope
• Observation of Nagaoka Polarons in a Fermi-Hubbard Quantum Simulator
• Metallic ferromagnetism: Progress in our understanding of an old strong-coupling problem
• Nagaoka ferromagnetism in the two-dimensional infinite-U Hubbard model
• Ferromagnetism in the Hubbard model: instability of the Nagaoka state on the triangular, honeycomb and kagome lattices
• Directly imaging spin polarons in a kinetically frustrated Hubbard system
• Competing phases of the Hubbard model on a triangular lattice -- insights from the entropy
• Itinerant spin polaron and metallic ferromagnetism in semiconductor moiré superlattices
• The itinerant ferromagnetic phase of the Hubbard model
• Triangular lattice Hubbard model physics at intermediate temperatures
• Comprehensive mean-field analysis of magnetic and charge orders in the two-dimensional Hubbard model
• Itinerant ferromagnetism in a Fermi gas with contact interaction: Magnetic properties in a dilute Hubbard model
• Polaronic mechanism of Nagaoka ferromagnetism in Hubbard models
• Nagaoka ferromagnetism in doped Hubbard models in optical lattices
• Proposal for asymmetric photoemission and tunneling spectroscopies in quantum simulators of the triangular-lattice Fermi-Hubbard model
• Noncollinear and noncoplanar magnetic order in the extended Hubbard model on anisotropic triangular lattice
• Quantum Monte Carlo simulations of infinitely strongly correlated fermions
• Spin-polarons and ferromagnetism in doped dilute Wigner-Mott insulators
• Spiral to stripe transition in the two-dimensional Hubbard model
• Interplay of spin and charge order in the electron-doped cuprates
• Superconductivity in doped triangular Mott insulators: the roles of parent spin backgrounds and charge kinetic energy
• Frustration induced Itinerant Ferromagnetism of Fermions in Optical Lattice
• Mean Field Study of Superconductivity in the Square Lattice $t$-$J$ Model with Three-Site Hopping