Spin texture and circular dichroism in photoelectron spectroscopy from the topological insulator Bi2Te3: first-principles photoemission calculations.

By relativistic first-principles photoemission calculations for the topological insulator Bi2Te3, we study how the spin texture of the Dirac state manifests itself in circular dichroism. On one hand, there are significant modifications of the initial state's spin texture, which are explained by final-state effects and the symmetry of the photoemission setup. On the other hand, a highly symmetric setup allows us to draw conclusions about the detailed Dirac state's spin texture. Our study supports that circular dichroism in angular distribution successfully complements spin- and angle-resolved photoelectron spectroscopy from topological insulators.