Topological insulators (TIs) of the bismuth telluride type are the most investigated among TIs. However, the studies were focused solely on the natural cleavage surface (111) which exhibits a slightly anisotropic Dirac state. Being a strong TI, ${\mathrm{Bi}}_2{\mathrm{Te}}_3$ should support topological surface states (TSSs) on any surface. Up to now, direct ARPES measurements of such surfaces have not been performed due to the complexity of preparing the surfaces different from (111). The few early density functional theory (DFT) studies were done for arbitrary side surfaces. In this study, we succeeded in preparing a side surface of a satisfactory quality for ARPES measurements. Also, using the DFT calculations, we explicitly showed the cause of the giant anisotropy of the TSS and its dependence on the projection of the bulk states onto the selected crystallographic plane. Calculations of the surface spectra for several planes that can form facets on the prepared side surface made it possible to identify the $\left(10\overline{1}\right)$ surface, the spectrum of which is in perfect agreement with the ARPES measurements.

Close

PrevNext

View figure in article

• Electronic structure
• First-principles calculations
• Surface states
• Topological materials
• Angle-resolved photoemission spectroscopy
• Atomic force microscopy
• Low-energy electron diffraction