Fig. 1: Monolayer 1T-TaS₂ structure in the shape of an ET bounded by a 1H-TaS₂ monolayer.

a A schematic picture of the left-handed packing of polarons in a C superlattice within an ET of outer dimensions 16a (inner dimensions l = 11a), where a = 0.33 Å is the lattice constant. The CCDW superlattice vector \({\boldsymbol{A}}\) is shown in terms of the lattice vectors a and b. The unit cells of the 1T and 1H crystal structures are shown in the insert. b The schematic structure of ETs on top of a 1T-TaS₂ substrate. c Ideal polaron packing in L and R-handed CCDW superlattices. d A phase diagram showing the charge density wave ordering transitions of the 1T- and 2H- polytypes as a function of temperature. The measurement temperature and phase transition temperatures are indicated. e A band diagram of the 1T-1H boundary. An edge state of width w forms within the 1T phase as a result of band bending (see Supplementary information). f An STM image of different sized a 1T-TaS₂ \(ETs\) embedded laterally within a 1H-TaS₂ monolayer on the surface of a 1T-TaS₂ single crystal. Note the ubiquitous presence of the edge state. The insert (bottom-left) shows a high-resolution image of a small ET with 6 polarons. More images are shown in the Supplementary information. g, h Fourier transforms of the 1H and 1T regions respectively. The \(\sqrt{13} \;\times\sqrt{13}\) CCDW SL and CL peaks are indicated. A peak attributed to the polarons ordered parallel to the edge of the ETs is also indicated (E).