Schematic of the three-dimensional wave guide mesh lattice that implements the proposed protocol in an entirely passive setting. Shown is one transverse unit cell as well as the sections of wave guides from the adjacent unit cells it interacts with in the course of the driving cycle. The sublattices A and B are indicated by the respective colours (dark/light grey) of the wave guides, and the regions with deliberately introduced losses are shaded purple. More details are provided in Supplementary Fig. 2.
