Tracking the pair of counter-propagating topological edge channels associated with the two sublattices (dashed magenta outlines). Shown are the intensity distributions after two driving periods as observed at the output facet of the sample when injecting light into specific edge sites (highlighted in orange). Note that, while both channels flow along the outermost sites of the x edges (orange arrows), their paths are offset by half a unit cell (green rhombus) along the y edges. As a result, the clockwise-propagating channel of sublattice A shifts to bypass the deliberately induced defect in the lower right-hand corner (right panel of a ), while the channel of sublattice B remains unaffected.
