Tunable excitonic metamaterials with one- and two-dimensional semiconductors

Excitons are formed by electron-hole pairs that are Coulomb bound to one another, and they dominate the optical properties of semiconductors that host them. Since the light-matter interaction depends on the dipole moment, as opposed specifically to plasmons that depend on the density of free-carriers, excitons are much more tunable than other resonances and free-carrier effects. We will demonstrate this in two systems in this talk. 1. 2D exciton semiconductor superlattices. 2. Single walled semiconducting carbon nanotubes.