Real-space observation of a time-reversal invariant topological state in twisted bilayer InSe.

ABSTRACT: The moiré superlattice formed by van der Waals (vdW) stacking of two-dimensional (2D) monolayers with a twist angle can give rise to a variety of novel correlated physical phenomena. In this study, we propose that a 2D semiconductor composed of vdW layers with band edge states extended into the interlayer region can host time-reversal-invariant topological states, as demonstrated by density functional theory and tight-binding calculations. This emergent physics in moiré superlattices is experimentally verified in a twisted bilayer InSe with a twisting angle of θ = 7.34°. Using scanning tunneling microscopy/spectroscopy (STM/STS), we observed topological edge modes associated with the Z₂ topological metal state at the moiré domain boundary, while these states are absent in the bi

SUBMITTER: Tian D 

PROVIDER: S-EPMC12559410 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature