人工范德瓦尔斯异质结构中的多铁性量子点

中文摘要 AI 辅助

量子点（QDs）为工程化量子受限电子态提供了一个多功能平台，这些电子态具有与光电子学、自旋电子学和量子技术相关的功能。尽管在将受限态与自旋、谷、拓扑或铁电自由度耦合方面已取得重大进展，但实现一种量子限制同时与磁性和铁电性交织的多铁性量子点仍然难以捉摸。在此，我们在超高真空条件下通过分子束外延生长的人工范德瓦尔斯异质结构中工程化了一种多铁性量子点。该异质结构由沉积在层状磁体CrBr$_2$上的铁电SnTe纳米岛组成，并支撑在高定向热解石墨上。结合扫描隧道显微镜和光谱学与从头计算及低能紧束缚模型，我们证明了SnTe岛内受限的自旋极化离散电子态的出现。值得注意的是，量子点的光谱响应强烈依赖于SnTe纳米岛的铁电畴构型，展示了原子尺度上量子限制、磁交换和铁电序之间的相互作用。我们的结果确立了工程化范德瓦尔斯异质结构作为多铁性量子限制的平台，并为电可调谐量子自旋电子器件开辟了新途径。

英文摘要

Quantum dots (QDs) provide a versatile platform for engineering quantum-confined electronic states with functionalities relevant for optoelectronics, spintronics, and quantum technologies. While substantial progress has been achieved in coupling confined states to spin, valley, topological, or ferroelectric degrees of freedom, the realization of a multiferroic QD in which quantum confinement simultaneously intertwines with magnetism and ferroelectricity remains elusive. Here, we engineer a multiferroic QD in an artificial van der Waals heterostructure grown by molecular beam epitaxy under ultra-high-vacuum conditions. The heterostructure consists of ferroelectric SnTe nanoislands deposited on the layered magnet CrBr$_2$ supported on highly oriented pyrolytic graphite. Combining scanning tunneling microscopy and spectroscopy with ab initio calculations and low-energy tight-binding models, we demonstrate the emergence of spin-polarized discretized electronic states confined within the SnTe islands. Remarkably, the spectroscopic response of the QD strongly depends on the ferroelectric domain configuration of the SnTe nanoislands, demonstrating an interplay between quantum confinement, magnetic exchange, and ferroelectric order at the atomic scale. Our results establish engineered van der Waals heterostructures as a platform for multiferroic quantum confinement and open new routes toward electrically tunable quantum spintronic devices.

发表机构

• Aalto University（阿尔托大学）
• University of Jyväskylä（于韦斯屈莱大学）

机构由 AI 辅助整理，请以论文原文为准。

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6 pages, 5 figures