Fig. 1.

STM topography and dI/dV spectra of single-layer 1T’-WTe₂ grown on BLG/SiC(0001). a Atomic model of the single-layer 1T’-WTe₂ structure grown on bilayer graphene /SiC substrate. b Atomic resolution STM image of the single-layer 1T’-WTe₂ surface (5 × 5 nm², U = + 15 mV, I_t = 300 pA). The length of the scale bar is 1.0 nm. The right half of the STM image is overlaid by the lattice of 1T’-WTe₂ with the top-layer Te atoms represented by yellow balls. c The corresponding Brillion Zone of single-layer 1T’-WTe₂. The locations of the minimum of conduction band are marked by red dots and labeled by Λ. d Spatial variation of dI/dV spectra (U = + 100 mV, I_t = 200 pA) taken at 128 locations along a line of ~16 nm. The red and blue arrows mark the energy gap at E_F, and the intensity minimum. e, f Two typical dI/dV maps (18 × 18 nm²) taken on the single-layer 1T’-WTe₂ terrace. U = + 70 mV for e and U = −100 mV for f, I_t = 100 pA. The length of the scale bar is 3.6 nm. The QPI-induced spatial modulations are clearly identified