Electrostatic and thermal control of Dyakonov–Tamm waves guided by a graphene-coated structurally chiral medium

The canonical problem for the propagation of a Dyakonov-Tamm Wave (DTW) guided by the surface of a structurally chiral medium coated by a graphene monolayer was numerically solved. The phase speed and propagation distance of the DTW propagating along a fixed direction in the graphene plane were computed in relation to the temperature and an external electrostatic field, both affecting the conductivity of graphene. At least one DTW propagates in any propagation direction, whereas two DTWs propagate in some limited ranges of directions. The phase speed is practically independent of the temperature and the electrostatic field. On the contrary, the propagation distance is noticeably affected by both parameters.