Dyakonov-Tamm waves guided by the planar interface of an isotropic dielectric material and an electro-optic ambichiral Reusch pile

The existence of an electromagnetic surface wave-classified as a Dyakonov-Tamm wave-guided by the planar interface of an isotropic, homogenous, dielectric material and an electro-optic ambichiral Reusch pile was theoretically established for various values of a dc electric field applied normal to the interface. For low magnitudes of the dc electric field, the spread of values of the refractive index n_s of the isotropic partnering material supporting the surface waves is exceedingly small. A sufficient increase in the magnitude of the dc electric field considerably widens that range. The allowed propagation directions, in all cases, constitute an angular sector of several tens of degrees in width.