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.

6+12 pages, 3+3 figures; v3 (minor change)

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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