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arXiv · 1111.5413

Direct Observation of the Topological Surface States in Lead-Based Ternary Telluride Pb(Bi1-xSbx)2Te4

S. Souma·K. Eto·M. Nomura·K. Nakayama·T. Sato·T. Takahashi·Kouji Segawa·Yoichi Ando
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Abstract

We have performed angle-resolved photoemission spectroscopy on Pb(Bi1-xSbx)2Te4, which is a member of lead-based ternary tellurides and has been theoretically proposed as a candidate for a new class of three-dimensional topological insulators (TIs). In PbBi2Te4, we found a topological surface state with a hexagonally deformed Dirac-cone band dispersion, indicating that this material is a strong TI with a single topological surface state at the Brillouin-zone center. Partial replacement of Bi with Sb causes a marked change in the Dirac carrier concentration, leading to the sign change of Dirac carriers from n-type to p-type. The Pb(Bi1-xSbx)2Te4 system with tunable Dirac carriers thus provides a new platform for investigating exotic topological phenomena.

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S. Souma, K. Eto, M. Nomura, K. Nakayama, T. Sato, T. Takahashi, Kouji Segawa, Yoichi Ando. 2011-11-23. Direct Observation of the Topological Surface States in Lead-Based Ternary Telluride Pb(Bi1-xSbx)2Te4. https://doi.org/10.1103/physrevlett.108.116801

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