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arXiv · 1209.4263

Single Dirac-cone on the Cs-covered topological insulator surface Sb2Te3(0001)

Christoph Seibel·Henriette Maaß·Minoru Ohtaka·Sebastian Fiedler·Christian Jünger·Chul-Hee Min·Hendrik Bentmann·Kazuyuki Sakamoto·Friedrich Reinert
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Abstract

Using angle-resolved photoelectron spectroscopy we investigate the surface electronic structure of the three-dimensional topological insulator (TI) Sb2Te3(0001). Our data show the presence of a topological surface state in the bulk energy gap with the Dirac-point located above the Fermi level. The adsorption of Cs-atoms on Sb2Te3(0001) gives rise to a downward energy shift of the electronic valence band states which saturates at a value of ~200 meV. For the saturation coverage the Dirac-point of the linearly dispersive surface state resides in close proximity to the Fermi level. The electronic structure of the Cs/Sb2Te3 interface therefore considerably deviates from previously studied metal-TI interfaces based on the isostructural compound Bi2Se3 which points to the importance of atomic composition in these hetero systems.

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Christoph Seibel, Henriette Maaß, Minoru Ohtaka, Sebastian Fiedler, Christian Jünger, Chul-Hee Min, Hendrik Bentmann, Kazuyuki Sakamoto, Friedrich Reinert. 2012-09-19. Single Dirac-cone on the Cs-covered topological insulator surface Sb2Te3(0001). https://doi.org/10.1103/physrevb.86.161105

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