|Topological physics focuses on researching the properties that are invariant under various deformations or stable against external perturbations. The concept was first found in condensed matter physics and has been successfully transferred into classical systems, including photonics, phononics and mechanics. |
Metamaterials, made from assemblies of multiple elements fashioned from composite materials such as metals or plastics, has offers a great platform for various topological phase realizations. Especially, it always supports wide band gap and clear band structure environment for studying nontrivial features. Except benefiting from the spatial symmetry analysis in metamaterials, it also paves the way towards involving internal degree of freedom, such as glimpsing topological nature of transversality in electromagnetism. Topological metamaterials are expected to have a rapid development in the next decade.