Local optical conductivity of bilayer graphene with kink potential

Abstract

We study the optical response of bilayer graphene with a kink potential composed of a domain wall separating two AB regions with opposite interlayer biases. The band structure and the local optical conductivity in real space are investigated in detail based on a continuum model. We find that the one-dimensional chiral states localized at the domain wall contribute significantly to the local optical conductivity, which shows a clear distinction in different regions. The effects of domain wall states on optical conductivity can be detected by spatially and frequency-resolved spectroscopic features. From the spectrum at various Fermi energies, important features in the band structure such as the energy separation between two chiral states can be directly measured. When the domain wall region is broad, the spatial distribution of local optical conductivity can provide important information on the bound states as well as the topological domain wall states.