Undamped transverse electric mode in undoped two-dimensional tilted Dirac cone materials

Abstract

Transverse electric (TE) modes cannot propagate through the conducting solids. This is because the continuum of particle-hole excitations of conductors contaminates with the TE mode which damps it out. But in solids hosting tilted Dirac cone that admit a description in terms of a modified Minkowski space-time, the new space-time structure remedies this issue and therefore a tilted Dirac cone material (TDM) supports the propagation of an undamped TE mode which is sustained by charge density fluctuations. The resulting TE mode propagates at fermionic velocities ${v}_{F}$, which implies (i) it is strongly confined to the surface of the two-dimensional (2D) TDM and (ii) the TDM acts as a high refractive index $n=c/{v}_{F}\ensuremath{\sim}{10}^{2}$ medium for TE modes.