Topological insulators are materials in which the electrons can only move along the surface while the core remains an insulator. In some unique circumstances when superconductivity is induced the electrons can move without any interference even when impurities are present in the insulator. Using the infamous logic: “If it works for particles, why not waves” the study of topological photonics was created. Through meticulous design, materials can be created that interact with light in very unique ways using topological mathematics as a base. These materials are exclusively 2D existing only as a single scattering layer for the light. One of the most interesting discoveries was that much like the electrons, the photons were willing to bypass any impurities that would normally cause them to be reflected. Light’s behaviour in these materials has greatly developed our ideas about electromagnetic interactions in solids relating to both their transmission and scattering. The disadvantage being that there is only so much that can be done when your working in only two dimensions.
However a recent paper has shown that it is at least theoretically possible to create a 3 dimensional topological system if it is created inside a dielectric material. This insures that the electric and magnetic field interact in such a way to produce a synthetic gauge field, an effective field which is produced by the Lorentz force and the Coriolis force (which is in itself imaginary), which causes Electrons to begin to display Dirac distributions. Now that it has been shown to be plausible that 3D photonic topologies can be created it is now just a question of how to manufacture one and if it was to be manufactured what effects would it demonstrate.