Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767Palaiseau, France.
CSIC and BIST, Campus UAB, Catalan Institute of Nanoscience and Nanotechnology (ICN2), Bellaterra, 08193Barcelona, Spain.
Nano Lett. 2023 Jan 11;23(1):34-41. doi: 10.1021/acs.nanolett.2c03113. Epub 2022 Dec 19.
2D materials offer the ability to expose their electronic structure to manipulations by a proximity effect. This could be harnessed to craft properties of 2D interfaces and van der Waals heterostructures in devices and quantum materials. We explore the possibility to create an artificial spin polarized electrode from graphene through proximity interaction with a ferromagnetic insulator to be used in a magnetic tunnel junction (MTJ). Ferromagnetic insulator/graphene artificial electrodes were fabricated and integrated in MTJs based on spin analyzers. Evidence of the emergence of spin polarization in proximitized graphene layers was observed through the occurrence of tunnel magnetoresistance. We deduced a spin dependent splitting of graphene's Dirac band structure (∼15 meV) induced by the proximity effect, potentially leading to full spin polarization and opening the way to gating. The extracted spin signals illustrate the potential of 2D quantum materials based on proximity effects to craft spintronics functionalities, from vertical MTJs memory cells to logic circuits.
二维材料提供了通过近场效应来操纵其电子结构的能力。这可以用于在器件和量子材料中设计二维界面和范德瓦尔斯异质结构的性质。我们探索了通过与铁磁绝缘体的近场相互作用，从石墨烯中制造人工自旋极化电极的可能性，该电极将用于磁隧道结 (MTJ)。制造了铁磁绝缘体/石墨烯人工电极，并基于自旋分析器将其集成到 MTJ 中。通过隧道磁电阻的出现，观察到了在近邻化石墨烯层中出现自旋极化的证据。我们推断出近场效应诱导了石墨烯的狄拉克能带结构（约 15 meV）的自旋相关劈裂，这可能导致完全的自旋极化并为栅极开辟了道路。提取的自旋信号说明了基于近场效应的二维量子材料在从垂直 MTJ 存储单元到逻辑电路的自旋电子学功能方面的潜力。
