Schematic depiction of triplon excitations in the sVBS phase. (a) shows a simple triplon excitation where a single valence bond is broken, and (b), (c) show examples of spinons propagating in different directions. In (d) the spinons move by a combination of moves from (b) and (c). The original position of the spinons and the original valence bond patterns are shown with light colors. Domain walls are indicated by gray lines in (d).