Microwave edge modes on a metasurface with glide symmetry

In this work we study planar metasurfaces comprised of two layers of hexagonal arrays of circular metal patches. This two-layer geometry supports a bound surface wave that propagates along the x direction. In our study, each metasurface is infinitely periodic in one direction (x) but only a few periods wide in the orthogonal direction (y). Through experiments and modeling we find evidence of a localized edge mode whose existence is dependent on the relative alignment of the two layers. This edge mode is used to guide the propagation of electromagnetic energy around both triangular and hexagonal shapes.