Interference in edge-scattering from monocrystalline gold flakes [Invited]

We observe strongly dissimilar scattering from the two types of sidewall configurations (here referred to as “edges”) in hexagonal quasi-monocrystalline gold flakes with thicknesses around 1 micron. As the origin of the phenomena, we identify the interference between a direct, quasi-specular scattering and an indirect scattering process involving an intermediate surface-plasmon state. The dissimilarity between the two types of edges is a direct consequence of the three-fold symmetry around the [111]-axis and the intrinsic chirality of a face-centered cubic lattice. We propose that this effect can be potentially used to estimate dielectric function of the monocrystalline gold.