Document Type

Article

Publication Date

2018

College/Unit

Eberly College of Arts and Sciences

Department/Program/Center

Physics and Astronomy

Abstract

One of the most striking properties of three-dimensional topological insulators (TIs) is spin-momentum locking, where the spin is locked at right angles to momentum and hence an unpolarized charge current creates a net spin polarization. Alternatively, if a net spin is injected into the TI surface state system, it is distinctively associated with a unique carrier momentum and hence should generate a charge accumulation, as in the so-called inverse Edelstein effect. Here using a Fe/Al2O3/BN tunnel barrier, we demonstrate both effects in a single device in Bi2Te3: the electrical detection of the spin accumulationgenerated by an unpolarized current flowing through the surface states, and that of the charge accumulation generated by spins injected into the surface state system. This work is the first to utilize BN as part of a hybrid tunnel barrier on TI, where we observed a high spin polarization of 93% for the TI surfaces states. The reverse spin-to-charge measurement is an independent confirmation that spin and momentum are locked in the surface states of TI, and offers additional avenues for spin manipulation. It further demonstrates the robustness and versatility of electrical access to the spin system within TI surface states, an important step towards its utilization in TI-based spintronics devices.

Source Citation

Li, C. H., van ‘t Erve, O. M. J., Yan, C., Li, L., & Jonker, B. T. (2018). Electrical Detection of Charge-to-spin and Spin-to-Charge Conversion in a Topological Insulator Bi2Te3 Using BN/Al2O3 Hybrid Tunnel Barrier. Scientific Reports, 8(1). https://doi.org/10.1038/s41598-018-28547-y

Comments

Open Access This article is licensed under a Creative Commons Attribution 4.0 International

License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Cre- ative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not per- mitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

© The Author(s) 2018

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