Giant proximity exchange and flat Chern band in 2D magnet-semiconductor heterostructures

Abstract

Van der Waals (vdW) heterostructures formed by two-dimensional magnets and semiconductors have provided a fertile ground for fundamental science and for spintronics. We present first-principles calculations finding a proximity exchange splitting of 14 meV equivalent to an effective Zeeman field of 120 T in the vdW magnet-semiconductor heterostructure MoS${}_2$/CrBr${}_3$, leading to a 2D spin-polarized half-metal with carrier densities ranging up to $10^{13}$ cm${}^{-2}$. We consequently explore the effect of large exchange coupling on the electronic bandstructure when the magnetic layer hosts chiral spin textures such as skyrmions. A flat Chern band is found at a "magic" value of magnetization $\overline{m}\sim 0.2$ for Schrödinger electrons, and it generally occurs for Dirac electrons. The magnetic proximity induced anomalous Hall effect enables transport-based detection of chiral spin textures, and flat Chern bands provides an avenue for engineering various strongly correlated states.

5+4 pages, 7 figures; v2 accepted to Science Advances

References in corpus (16)

• Graphene Bilayers with a Twist
• Quantum anomalous Hall effect from intertwined moiré bands
• Bulk Topological Invariants in Noninteracting Point Group Symmetric Insulators
• Magic in twisted transition metal dichalcogenide bilayers
• Strain-induced partially flat band, helical snake states, and interface superconductivity in topological crystalline insulators
• Physical origin of giant excitonic and magneto-optical responses in two-dimensional ferromagnetic insulators
• Moiré skyrmions and chiral magnetic phases in twisted CrX${}_3$ (X $=$ I, Br, Cl) bilayers
• Properties and dynamics of meron topological spin textures in the two-dimensional magnet CrCl3
• Skyrmion formation in a bulk chiral magnet at zero magnetic field and above room temperature
• Spin moiré engineering of topological magnetism and emergent electromagnetic fields
• Magnetic moiré surface states and flat chern band in topological insulators
• Topological magnetic textures in magnetic topological insulators
• Magnetic skyrmion crystal at a topological insulator surface
• Twisted magnetic topological insulators
• Designing spin-textured flat bands in twisted graphene multilayers via helimagnet encapsulation
• Spin-textured Chern bands in AB-stacked transition metal dichalcogenide bilayers

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• Contrasting twisted bilayer graphene and transition metal dichalcogenides for fractional Chern insulators: an emergent gauge picture
• Minimal Fractional Topological Insulator in half-filled conjugate moiré Chern bands
• A Generic Topological Criterion for Flat Bands in Two Dimensions
• Riemann meets Goldstone: magnon scattering off quantum Hall skyrmion crystals probes interplay of symmetry breaking and topology
• Chiral superconductivity from spin polarized Chern band in twisted MoTe${}_2$
• Compressible quantum liquid with vanishing Drude weight
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• Unified Magnetoelectric Mechanism for Spin Splitting in Magnets
• Pathways from a chiral superconductor to a composite Fermi liquid
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• The electronic structure of intrinsic magnetic topological insulator MnBi2Te4 quantum wires
• Topological Order in Neural Wavefunctions
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