Work

Optimizing Bi2−xSbxTe3−ySey solid solutions to approach the intrinsic topological insulator regime

Year: 2011

Type: article

Abstract: To optimize the bulk-insulating behavior in the topological insulator materials having a tetradymite structure, we have synthesized and have characterized single-crystal samples of ${\mathrm{Bi}}_{2\text{\ensuremath{-}}x}{\mathrm{Sb}}_{x}{\mathrm{Te}}_{3\text{\ensuremath{-}}y}{\mathrm{Se}}_{y}$ solid solution at various compositions. We have elucidated that there are a series of intrinsic compositions where the acceptors and donors compensate each other and present a maximal bulk-insulating behavior. At such compositions, the resistivity can become as large as several $\ensuremath{\Omega}$ cm at low temperatures, and one can infer the role of the surface-transport channel in the nonlinear Hall effect. In particular, the composition of ${\mathrm{Bi}}_{1.5}{\mathrm{Sb}}_{0.5}{\mathrm{Te}}_{1.7}{\mathrm{Se}}_{1.3}$ achieves the lowest bulk carrier density and appears to be best suited for surface-transport studies.

Source: Physical Review B

DOI: 10.1103/physrevb.84.165311

Authors: Zhi Ren, A. A. Taskin, Satoshi Sasaki, Kouji Segawa, Yoichi Ando

Institutions: The Institute of Scientific and Industrial Research, The University of Osaka, The University of Osaka

Language: English

Topic: Topological Materials and Phenomena

Subfield: Condensed Matter Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: Asian Office of Aerospace Research and Development, Ministry of Education, Culture, Sports, Science and Technology, Japan Society for the Promotion of Science, Air Force Office of Scientific Research

Awards: G5605023542, G8192318976