Bi2:Bi2Te3 stacking influence on the surface electronic response of the topological insulator Bi4Te3

We report on the successful synthesis of a crystal of the strong topological insulator Bi4Te3 and the study of its surface electronic response. A combination of theoretical and experimental techniques allowed for a systematic study of the composition and electronic properties of the sample. These techniques include density functional theory (DFT), scanning tunneling microscopy and spectroscopy (STM-STS). DFT predicts that distinct surface topological states exist for the two surface terminations of Bi4Te3, i.e. Bi-2 and Bi2Te3. These terminations are also clearly distinguished in STS measurements, which allow choosing the main conducting channel through a combination of topography and electronic response. We find that the density of states are similar to those of their parent crystals Bi-2 and Bi2Te3, albeit shifted in energy.