Even in classical diffusive motion, topologically protected edge modes can be found

Classical analogs of solid state topological insulators, which support protected sound or light waves along their edges, are being realized in cutting-edge soft matter research. In a new paper published online in the Proceedings of the National Academy of Scienes, Kinjal Dasbiswas and collaborators find some surprising connections with topological band theory and edge phenomena even in the cases of diffusive motion in random walks and fluid flows. Matter and networks could then be classical, stochastic, and dissipative, and still support topological states.