Fig. 2: Continuous atomic arrangement during the chirality switching of the CDW superlattice.
a–c Atomic-resolution images of the same area of the 1T-NbSe2 island before (a) and after (b) boundary movement of chiral domains, demonstrating a chiral change from a coexistence of the L-R domain to a pure L domain (c). The upper part of each image is overlaid by a well-ordered lattice of gray balls, indicating that the top-layer Se lattice is continuous over the whole area from L to R domains. d–f Atomic model of SL 1T-NbSe2 with the shifted CDW domain boundary, describing the same area marked by the red frame in (a–c). The green and blue balls represent Se atoms in the SOD with left and right chiralities, respectively, while the gray balls show the Se atoms surrounding the SOD. All Se atoms (in blue, green, and gray) share the same periodic hexagonal lattice. g–i FFT images of (a–c) showing that both statuses I and II have two chiral sets of spots. In status III, there is a reduction to one set of spots for the CDW superlattice. The unit vectors of a1* and a2* in reciprocal space originated from the top-Se lattice, bL1* and bL2* from the L domain, and bR1* and bR2* from the R domain, respectively. Scanning parameters: a, −1.5 V, 1 nA. b and c, −1.5 V, 2 nA.
