Visualizing the Origins of Topology in tMoTe₂

The moiré superlattice formed in twisted molybdenum ditelluride (tMoTe₂) generates flat bands with nontrivial topology. When these bands are partially filled, strong Coulomb interactions lead to the emergence of integer and fractional quantum anomalous Hall (QAH) effects. Various experimental probes of these QAH states have solidified tMoTe₂ as a fruitful platform to study the interplay between topology and electron interactions, but several fabrication challenges have precluded studies on an atomic scale. Topology in tMoTe₂ is predicted to arise from a sub-moiré scale texture of the layer pseudospin, which describes the layer polarization of the flat band wavefunctions. This makes atomic-scale probes such as scanning tunneling microscopy and spectroscopy (STM-S) crucial for understanding the nature of topology in this system. Here we present an STM-S investigation of the layer pseudospin texture in neutral tMoTe₂. We identify spectroscopic signatures of the flat bands and find that they exhibit a spatially varying layer polarization that closely matches theoretical predictions. We additionally compare this to the localization of higher energy topologically trivial bands. These observations support the existence of a layer pseudospin texture in tMoTe₂ and suggest a direct connection between its structural properties and band topology.