Moiré superlattice and control of rotational order of C₆₀ on WTe₂

The emergence of controllable moiré patterns in heterostructures of atomically thin materials has generated a plethora of new phenomena, often including flat bands and strongly correlated states. The combination of 2D materials or van der Waals layered materials with highly ordered layers of conjugated organic molecules has been less explored, but offers the potential of creating moiré heterostructures with increased tunability. Here we show by means of ARPES, momentum microscopy and STM that this is indeed the case for a heterostructure of C₆₀ on the Weyl semimetal WTe₂. A full analysis of the interfacial atomic arrangement shows that this heterostructure exhibits static distortion waves where the resulting moiré potential is deep enough to cause periodic alignment of the rotational degree of freedom of C₆₀ on the WTe₂ surface. This produces periodically varying electric fields in this heterostructure, which may be important to control quantum degrees of freedom.