  The topological magnetoelectric effect (TME) is a unique macroscopic
manifestation of quantum states of matter possessing topological order and it
is described by axion electrodynamics. In three-dimensional topological
insulators, for instance, the axion coupling is of the order of the fine
structure constant, and hence a perturbative analysis of the field equations is
plenty justified. In this paper we use Green's function techniques to obtain
time-dependent solutions to the axion field equations in the presence of a
planar domain-wall separating two media with different topological order. We
apply our results to investigate the radiation of a short linear antenna near
the domain-wall.
