title: Massive Dirac quasiparticles in the optical absorbance of graphene, silicene, germanene, and tinene.
abstract: We present first-principles studies of the optical absorbance of the group IV honeycomb crystals graphene, silicene, germanene, and tinene. We account for many-body effects on the optical properties by using the non-local hybrid functional HSE06. The optical absorption peaks are blueshifted due to quasiparticle corrections, while the influence on the low-frequency absorbance remains unchanged and reduces to a universal value related to the Sommerfeld fine structure constant. At the Dirac points spin-orbit interaction opens fundamental band gaps; parabolic bands with a very small effective mass emerge. Consequently, the low-frequency absorbance is modified with a spin-orbit-induced transparency region and an increase of the absorbance at the fundamental absorption edge.
authors.affiliation: Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, D-07743 Jena, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Matthes
authors.forename: Olivia
authors.initials: O
authors.lastname: Pulci
authors.forename: Friedhelm
authors.initials: F
authors.lastname: Bechstedt