Imaging twisted MoTe₂ with scanning tunneling microscopy: Part 2

Twisted molybdenum ditelluride (tMoTe₂) has recently emerged as an exciting new platform to study strongly correlated topological states of matter. The moiré superlattice that arises from twisting two MoTe₂ monolayers generates flat bands that act as a platform for the fractional quantum anomalous Hall effect. The nature of the correlated ground states and their topology is intimately tied to the moiré lattice. Furthermore, this lattice can be tuned by applying a perpendicular electric field which modifies the layer polarization of charges. Though these effects have been studied macroscopically through electrical transport and optical spectroscopy, they have not yet been investigated on the atomic scale. This is in part due to challenges in fabricating vdW heterostructures with a pristine exposed tMoTe₂ surface, which we will discuss in the first part of this presentation. Here, we present direct visualization of the flat bands in tMoTe₂ with spatially resolved scanning tunneling microscopy and spectroscopy (STM/S) measurements acquired at different energies and band fillings. These measurements elucidate how the low energy states localize on the moiré scale. Our results shed light on the nature of the flat bands that underlie interaction-driven phenomena in tMoTe2 and will inform future studies of its integer and fractional quantum Hall states.