Extended Data Fig. 1: Conductive atomic force microscope (cAFM) measurements of tWTe₂ at room temperature.

a, Cartoon illustrations of the cAFM measurement on a few-layer hBN/tWTe₂/hBN stack on a Pd metal film pre-patterned on a SiO₂/Si chip. The inset illustrates the cross-section of the stack. A relatively thick (around 39 nm) hBN was used to mitigate the roughness of the metal surface. b, A cAFM image taken from a θ ≈ 5° tWTe₂ device, directly visualizing the moiré structure. The dashed-dot square locates a zoom-in scan, as shown in c. We comment on three aspects of the observations. (1) The measurement was taken at room temperature, where the transport shows no significant anisotropy. This is consistent with the fact the measured local conductance G varies only by a small amount at different tip locations in the map. (2) As shown in b and c, the small variations already allow us to clearly image the underlying moiré structure. (3) Our experimental resolution does not allow us to identify which one is the AA stripe or the AB stripe, but the map is clearly consistent with the pattern shown in Fig 1b, except with lattice relaxations. The relatively low and high conductance regions develop into stripes, with an inter-stripe distance approximately 7.1 nm, consistent with the expectation for a θ ≈ 5° tWTe₂ stack. (4) As WTe₂ is air sensitive, we have to use a few-layer hBN as a protecting layer and a sample fabrication process that minimizes the time for the sample exposed to air. The top surface of the thin hBN is left behind with polymer residues etc, which we believe could be the main source of the residue-like features in b and c. Our transport devices (devices no. 1 & no. 2 in the main text) use a top graphite gate that serves as a screening layer and hence the tWTe₂ channel is of much higher quality. Other details about the cAFM measurements can be found in the Methods.