Twist-angle evolution of the intervalley coherent antiferromagnet in twisted WSe2

Twisted transition metal dichalcogenides provide a tunable platform to realize a variety of correlated and topological phases, from Mott insulators and Wigner crystals to integer and fractional quantum Hall states. Recently, two experiments have also discovered a superconducting dome that appears in proximity to a correlated state in twisted WSe2 at two different twist angles [1,2]. Here, we study this correlated state, whose fluctuations could affect the nature of the superconducting pairing. Using Hartree-Fock in a three-band Wannierization of the continuum model, we find an instability towards an intervalley coherent antiferromagnet with \sqrt(3)x\sqrt(3) periodicity. In the weak coupling limit, the instability occurs along the van Hove singularity at a high density (n ~ 1.5 holes/moiré cell), and it continuously moves towards half filling (n=1) with increasing interaction. Before the instability reaches half-filling, the transition from the normal state at the low-density boundary is sharp, in agreement with the 5 degree twist angle sample [2]. The reconstructed Fermi surface could also explain the large Hall signal in this experiment. Finally, we discuss the possibility of incommensurate intervalley coherent order using the time-dependent Hartree-Fock method.

[1] Y. Xia, et al., arXiv:2405.14784 (2024).

[2] Y. Guo, et al., arXiv:2406.03418 (2024).