Perfect absorption by semi-infinite indefinite medium

We theoretically demonstrate that there is an angle of incidence and frequency at which a p-polarized electromagnetic wave can be perfectly absorbed without reflection by a semi-infinite space of lossy indefinite anisotropic medium. Unlike isotropic lossy materials (where the total absorption occurs for a finite-thickness layers only) in our case it happens for a lossy half-space. We show that this perfect absorption happens when the Zenneck wave guided by the surface of indefinite lossy medium becomes a homogenous plane wave.