The layer-dependent Hamiltonians of parallel-stacked ${\mathrm{MoTe}}_2$ and ${\mathrm{WSe}}_2$ homobilayer moiré materials are topologically nontrivial, 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 $t{\mathrm{WSe}}_2$ when the Fermi level is close to its $M$-point van Hove singularity and the displacement field is small. We combine density functional theory 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 $t{\mathrm{WSe}}_2$ at $\theta =2.7^{\circ }$ and $\theta =3.{65}^{\circ }$, we find that a layer antiferromagnet, a stripe spin-density wave, and the ferromagnetic Chern insulator 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.

Close

PrevNext

View figure in article

• Electronic structure
• Superconductivity
• Moire materials
• Narrow band gap systems
• Quantum many-body systems
• Unconventional superconductors
• Density functional theory
• First-principles calculations
• Green's function methods
• Path integrals
• t-J model