Weak Antilocalization and Anisotropic Magnetoresistance as a Probe of Surface States in Topological Bi2TexSe3-x Thin Films

Gregory M Stephen; Owen A Vail; Jiwei Lu; William A Beck; Patrick J Taylor; Adam L Friedman

doi:10.1038/s41598-020-61672-1

Weak Antilocalization and Anisotropic Magnetoresistance as a Probe of Surface States in Topological Bi₂Te_xSe_3-x Thin Films

Sci Rep. 2020 Mar 16;10(1):4845. doi: 10.1038/s41598-020-61672-1.

Authors

Gregory M Stephen¹, Owen A Vail², Jiwei Lu³, William A Beck², Patrick J Taylor², Adam L Friedman⁴

Affiliations

¹ Laboratory for Physical Sciences, 8050 Greenmead Dr., College Park, MD, 20740, United States. gstephen@lps.umd.edu.
² Army Research Laboratory, 2800 Powder Mill Rd., Adelphi, MD, 20783, United States.
³ Department of Materials Science and Engineering, University of Virginia, Charlottesville, VA, 22904, United States.
⁴ Laboratory for Physical Sciences, 8050 Greenmead Dr., College Park, MD, 20740, United States. afriedman@lps.umd.edu.

Abstract

Topological materials, such as the quintessential topological insulators in the Bi₂X₃ family (X = O, S, Se, Te), are extremely promising for beyond Moore's Law computing applications where alternative state variables and energy efficiency are prized. It is essential to understand how the topological nature of these materials changes with growth conditions and, more specifically, chalcogen content. In this study, we investigate the evolution of the magnetoresistance of Bi₂Te_xSe_3-x for varying chalcogen ratios and constant growth conditions as a function of both temperature and angle of applied field. The contribution of 2D and 3D weak antilocalization are investigated by utilizing the Tkachov-Hankiewicz model and Hakami-Larkin-Nagaoka models of magnetoconductance.