Stripe antiferromagnetism and chiral superconductivity in tWSe${}_2$

Abstract

The layer-dependent Hamiltonians of parallel-stacked MoTe${}_2$ and WSe${}_2$ homobilayer moiré materials are topologically non-trivial, both in real space and in momentum space, and have been shown to support integer and fractional quantum anomalous Hall states, as well as antiferromagnetic and superconducting states. Here, we address the interplay between the antiferromagnetic and superconducting states observed in tWSe${}_2$ when the Fermi level is close to its $M$-point van Hove singularity and the displacement field is small. We combine DFT with path-integrals to construct a minimal moiré band model that accounts for lattice relaxation along the $c$-axis and perform Hartree-Fock calculations to identify competing charge and spin ordered states. For tWSe${}_2$ at $\theta =2.7^{\circ }$ and $\theta =3.65^{\circ }$, we find that a layer antiferromagnet (AFM), a stripe spin-density-wave (SDW), and the ferromagnetic Chern insulator (FM) are the primary candidates for the ground state at zero displacement field, and argue that antiferromagnetic spin interactions on the next neighbor bond $J_2$ can induce a time-reversal symmetry breaking chiral superconducting state.

11 pages, 5 figures

References in corpus (27)

• High temperature fractional quantum Hall states
• Fractional quantum Hall states at zero magnetic field
• Nearly-flat bands with nontrivial topology
• Signatures of Fractional Quantum Anomalous Hall States in Twisted MoTe2 Bilayer
• Observation of Fractionally Quantized Anomalous Hall Effect
• Fractional quantum Hall effect in the absence of Landau levels
• Integer and fractional Chern insulators in twisted bilayer MoTe2
• Observation of integer and fractional quantum anomalous Hall effects in twisted bilayer MoTe2
• MATBG as Topological Heavy Fermion: I. Exact Mapping and Correlated Insulators
• Fractional Chern Insulator in Twisted Bilayer MoTe${}_2$
• Superconductivity in twisted bilayer WSe${}_2$
• Programming Correlated Magnetic States via Gate Controlled Moiré Geometry
• Gate-tunable heavy fermions in a moiré Kondo lattice
• Kinetic Magnetism in Triangular Moiré Materials
• Polarization-driven band topology evolution in twisted MoTe${}_2$ and WSe${}_2$
• Frustrated magnetic interactions in a Wigner-Mott insulator
• Interaction-driven topological phase diagram of twisted bilayer MoTe${}_2$
• Gate-tunable heavy fermion quantum criticality in a moiré Kondo lattice
• Nematic excitonic insulator in transition metal dichalcogenide moiré heterobilayers
• Bridging the small and large in twisted transition metal dicalcogenide homobilayers: a tight binding model capturing orbital interference and topology across a wide range of twist angles
• Multiferroicity and Topology in Twisted Transition Metal Dichalcogenides
• Twist-angle evolution of the intervalley-coherent antiferromagnet in twisted WSe${}_2$
• Theory of Topological Superconductivity and Antiferromagnetic Correlated Insulators in Twisted Bilayer WSe${}_2$
• Theory of intervalley-coherent AFM order and topological superconductivity in tWSe${}_2$
• Topological Chiral Superconductivity Mediated by Intervalley Antiferromagnetic Fluctuations in Twisted Bilayer WSe${}_2$
• Ab-initio study of the energy competition between Γand K valleys in bilayer transition metal dichalcogenides
• Angle evolution of the superconducting phase diagram in twisted bilayer WSe2