Spin-polarons and ferromagnetism in doped dilute Wigner-Mott insulators

Abstract

Moiré heterostructures of transition metal dichalcogenides exhibit Mott-insulating behaviour both at half-filling as well as at fractional fillings, where electronic degrees of freedom form self-organized Wigner crystal states. An open question concerns magnetic states obtained by lifting the pseudospin-1/2 degeneracy of these states at lowest temperatures. While at half-filling virtual hopping is expected to induce (weak) antiferromagnetic exchange interactions, these are strongly suppressed when considering $\text{dilute}$ filling fractions. We argue that instead a small concentration of doped electrons leads to the formation of spin-polarons, inducing ferromagnetic order at experimentally relevant temperatures. We predict explicit signatures of polaron-formation in the magnetization profile of the system.

arXiv comment6+12 pages, 3+3 figures; v3 (minor change)

References in corpus (31)

• Magic-angle graphene superlattices: a new platform for unconventional superconductivity
• Correlated Insulator Behaviour at Half-Filling in Magic Angle Graphene Superlattices
• Optical detection of Mott and generalized Wigner crystal states in WSe2/WS2 moiré superlattices
• Magic continuum in twisted bilayer WSe2
• Graphene Bilayers with a Twist
• Topological insulators in twisted transition metal dichalcogenide homobilayers
• Hubbard model physics in transition metal dichalcogenide moiré bands
• Abundance of correlated insulating states at fractional fillings of WSe${}_2$/WS${}_2$ moiré superlattices
• Moiré heterostructures as a condensed matter quantum simulator
• The Hubbard Model
• $\Gamma$-Valley Transition-Metal-Dichalcogenide Moirè Bands
• Fractional quantum anomalous Hall states in twisted bilayer MoTe${}_2$ and WSe${}_2$
• Programming Correlated Magnetic States via Gate Controlled Moiré Geometry
• Quantum Phase Diagram of a Moiré-Hubbard Model
• Gate-tunable heavy fermions in a moiré Kondo lattice
• Nagaoka ferromagnetism observed in a quantum dot plaquette
• Frustration- and doping-induced magnetism in a Fermi-Hubbard simulator
• Kinetic Magnetism in Triangular Moiré Materials
• Generalized Wigner crystallization in moiré materials
• Kinetic Antiferromagnetism in the Triangular Lattice
• Topological Phases in AB-Stacked MoTe${}_2$/WSe${}_2$: ${\mathbb{Z}}_2$ Topological Insulators, Chern Insulators, and Topological Charge Density Waves
• Quantum anomalous Hall effect from inverted charge transfer gap
• Non-local interactions in moiré Hubbard systems
• Observation of Spontaneous Ferromagnetism in a Two-Dimensional Electron System
• Topological Mott Insulator at Quarter Filling in the Interacting Haldane Model
• Chiral Kondo Lattice in Doped MoTe${}_2$/WSe${}_2$ Bilayers
• Itinerant spin polaron and metallic ferromagnetism in semiconductor moiré superlattices
• Pairing from strong repulsion in triangular lattice Hubbard model
• Kagome chiral spin liquid in transition metal dichalcogenide moiré bilayers
• Interstitial-induced ferromagnetism in a two-dimensional Wigner crystal
• Wigner Crystals in Two-Dimensional Transition-Metal Dichalcogenides: Spin Physics and Readout

Cited by in corpus (6)

• Programming Correlated Magnetic States via Gate Controlled Moiré Geometry
• Quantum Melting of Generalized Wigner Crystals in Transition Metal Dichalcogenide Moiré Systems
• Geometric Frustration Assisted Kinetic Ferromagnetism in Doped Mott Insulators
• Electronic phonon-induced magnetism in moiré Mott-Wigner crystals
• Insulating charge transfer ferromagnetism
• Doping-induced Quantum Anomalous Hall Crystals and Topological Domain Walls