Parfenov Oleg E, Averyanov Dmitry V, Sokolov Ivan S, Mihalyuk Alexey N, Kondratev Oleg A, Taldenkov Alexander N, Tokmachev Andrey M, Storchak Vyacheslav G
National Research Center "Kurchatov Institute", Kurchatov Sq. 1, 123182 Moscow, Russia.
Institute of High Technologies and Advanced Materials, Far Eastern Federal University, 690950 Vladivostok, Russia.
J Am Chem Soc. 2025 Jul 9;147(27):23857-23867. doi: 10.1021/jacs.5c06305. Epub 2025 Jun 24.
Altermagnets, an emerging class of magnetic materials, combine zero net magnetization with strong spin-based phenomena that makes them highly attractive for spintronics. Practical applications require altermagnets to be brought to the nanoscale; however, this area is scarcely explored experimentally. Recently, films of the Weyl altermagnet GdAlSi have been studied down to a single monolayer to reveal symmetry breaking and thickness-dependent evolution of its properties. Here, we show that the structure of GdAlSi allows for further miniaturization, making 1/2 monolayer a basic building block for construction of 2D spintronic materials. Epitaxy of 1/2 monolayer of GdAlSi results in a film with nearly compensated magnetic moments; it exhibits a semiconducting behavior, in contrast to the metallic monolayer and the bulk. The semiconductor demonstrates colossal negative magnetoresistance, exceeding that in a monolayer by more than an order of magnitude. The anomalous Hall effect in 1/2 monolayer of GdAlSi follows the universal scaling relation for magnetic semiconductors. The fabricated material is seamlessly integrated with Si, thus holding high promise for ultracompact spintronics.
交替磁体是一类新兴的磁性材料，它将零净磁化与基于自旋的强现象相结合，这使得它们在自旋电子学领域极具吸引力。实际应用要求将交替磁体缩小到纳米尺度；然而，这一领域在实验上几乎未被探索。最近，对魏尔交替磁体GdAlSi的薄膜进行了研究，直至单个单层，以揭示其对称性破缺及其性质随厚度的演变。在此，我们表明GdAlSi的结构允许进一步小型化，使1/2单层成为构建二维自旋电子材料的基本构建单元。1/2单层GdAlSi的外延生长形成了一种磁矩几乎被补偿的薄膜；与金属单层和块体相比，它表现出半导体行为。该半导体表现出巨大的负磁阻，比单层中的负磁阻高出一个多数量级。1/2单层GdAlSi中的反常霍尔效应遵循磁性半导体的通用标度关系。所制备的材料与硅无缝集成，因此在超紧凑自旋电子学方面具有很高的前景。
