Edge states in honeycomb structures

Understand

An edge state is a time-harmonic solution of a conservative wave system, e.g.

• Schroedinger, Maxwell, which is propagating (plane-wave-like) parallel to, and localized transverse to, a line-defect or "edge".
• Topologically protected edge states are edge states which are stable against spatially localized (even strong) deformations of the edge.
• First studied in the context of the quantum Hall effect, protected edge states have attracted huge interest due to their role in the field of topological insulators.