Scalable quaternary topological insulator for low-power spintronics

IF 3.8 2区物理与天体物理 Q2 PHYSICS, APPLIED

Applied Physics Letters Pub Date : 2026-10-05 DOI:10.1063/5.0344386

Qi Zhang,Hanyuan Guo,Pengxiang Zhao,Xu Liu,Wei Gao,Baoshan Cui,Yalu Zuo,Xiaoxi Liu,Yang Ren,Li Xi

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引用次数: 0

Abstract

Topological insulators (TIs) with spin-momentum-locked surface states exhibit high charge-to-spin (C2S) conversion efficiency. However, binary and ternary TIs are constrained by a narrow tunable composition window for their insulating bulk states, which limits spintronic performance due to interference from bulk conduction. This work reports the development of a high-quality quaternary TI, [Sb2Te3(5−t)/Bi2Se3(t)]4, fabricated via scalable magnetron sputtering. By tuning the Bi2Se3 layer thickness, the quaternary TI exhibits high resistivity and low carrier concentration, effectively suppressing bulk conduction across a broad tunable window. Over a wide Bi2Se3 thickness range (t = 0.2–1.5 nm, corresponding to 3%–23% Bi2Se3 content), a high spin Hall angle (θSH) of 0.4–0.99 is maintained. Furthermore, in heterostructures based on this quaternary TI, the critical magnetization switching current density drops to as low as 3.3 × 105 A/cm2, which is two orders of magnitude lower than that of heavy metal Pt. Owing to the large spin Hall angle, the quaternary TI also exhibits power consumption approximately 20 times lower than ternary TIs for t = 0.2–1.5 nm. These results confirm that scalable quaternary TIs enable low-power spintronic devices with enhanced efficiency and processing flexibility, paving the way for advanced spintronic applications.

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用于低功率自旋电子学的可伸缩四元拓扑绝缘体

具有自旋-动量锁定表面态的拓扑绝缘体具有较高的电荷-自旋转换效率。然而，二元和三元ti受到其绝缘体态的窄可调组成窗口的限制，这限制了自旋电子性能，这是由于体传导的干扰。本文报道了采用可伸缩磁控溅射法制备的高质量季系钛[Sb2Te3(5−t)/Bi2Se3(t)]4。通过调整Bi2Se3层厚度，第四系TI表现出高电阻率和低载流子浓度，有效地抑制了宽可调窗口内的体传导。在较宽的Bi2Se3厚度范围内（t = 0.2 ~ 1.5 nm，对应Bi2Se3含量3% ~ 23%），自旋霍尔角（θSH）保持在0.4 ~ 0.99之间。此外，在基于四元TI的异质结构中，临界磁化开关电流密度降至3.3 × 105 A/cm2，比重金属Pt低两个数量级。由于自旋霍尔角大，在t = 0.2-1.5 nm时，四元TI的功耗也比三元TI低约20倍。这些结果证实，可扩展的四元钛使低功率自旋电子器件具有更高的效率和加工灵活性，为先进的自旋电子应用铺平了道路。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Applied Physics Letters 物理-物理：应用

CiteScore

6.40

自引率

10.00%

发文量

1821

审稿时长

1.6 months

期刊介绍： Applied Physics Letters (APL) features concise, up-to-date reports on significant new findings in applied physics. Emphasizing rapid dissemination of key data and new physical insights, APL offers prompt publication of new experimental and theoretical papers reporting applications of physics phenomena to all branches of science, engineering, and modern technology. In addition to regular articles, the journal also publishes invited Fast Track, Perspectives, and in-depth Editorials which report on cutting-edge areas in applied physics. APL Perspectives are forward-looking invited letters which highlight recent developments or discoveries. Emphasis is placed on very recent developments, potentially disruptive technologies, open questions and possible solutions. They also include a mini-roadmap detailing where the community should direct efforts in order for the phenomena to be viable for application and the challenges associated with meeting that performance threshold. Perspectives are characterized by personal viewpoints and opinions of recognized experts in the field. Fast Track articles are invited original research articles that report results that are particularly novel and important or provide a significant advancement in an emerging field. Because of the urgency and scientific importance of the work, the peer review process is accelerated. If, during the review process, it becomes apparent that the paper does not meet the Fast Track criterion, it is returned to a normal track.