Spin Orbit functionalized GRAPHene for resistive-magnetic MEMories

对高密度、低功耗、快速自旋逻辑器件的需求，要求材料的组合既能提供合适的自旋传输通道，具有较长的自旋寿命和自旋传播能力，又能提供拓扑稳定的自旋织构，可以作为快速信息载体。利用特定多层结构中电子的自旋和动量自由度（spin - orbitronics， SO），可以满足未来几年自旋电子技术发展的先决条件。此外，在石墨烯(Gr)/铁磁（FM）界面上发现强Dzyaloshinskii - Moriya相互作用（DMI）是促进SO技术的关键一步，使电子控制（拓扑保护的）磁性结构的传输和操纵成为可能。该联盟的合作伙伴已经证明了通过金属嵌入调整SOC和重要的磁相互作用的能力，包括垂直各向异性，层间偶极场或界面DMI，通过层工程来控制磁畴壁和skyrmions的手性，检测电纳米自旋织构，实现石墨烯介导的FMs之间的反铁磁耦合（AFC）。最后，设计铁电用于各种类型的铁电存储器。SOgraphMEM项目旨在i)功能化SOC诱导参数，ii)表征，以及iii)测试在室温下工作的基于石墨烯的自旋轨道系统/器件，利用Gr层下的FM超薄膜，重金属（HM）的非磁性薄膜和铁电（FE）化合物（掺杂hfo2， HfZrO2）的优势。我们的目标是利用FE的极化，以最终实现压控电阻和磁开关器件。我们将采用一种特定的方法来制造堆叠，其顺序为FE / Gr / FM / HM到绝缘氧化物上。为了稳定自旋织构，我们还将探索通过Gr在合成反铁磁（SAF）堆栈中使用AFC，即FM2 / Gr / FM1。将讨论与电场控制有关的界面- soc诱导效应的不同问题：a)电场对表面磁各向异性和DMI的影响，b)自旋轨道转矩（SOT）和自旋传递转矩（STT）随外加磁场和/或电场的变化特性，c) gr中感应磁矩的磁各向异性。从实际应用角度来看，SOgraphMEM将为开发超越摩尔定律的下一代自旋电子学器件开辟道路，具有低功率、高速度和大密度的特点。以及高效的自旋注入/检测。

The demand for high density, low power and fast spin logic devices requires the combination of materials that can provide suitable spin transport channels with long spin lifetime and spin propagation, as well as topologically stable spin textures that can act as fast information carriers. These prerequisites for the development of spintronic technology in next years can be fulfilled by exploiting the spin and momentum degrees of freedom of electrons (Spin-Orbitronics, SO) in specific multi-layered structures. In addition, the discovery of a strong Dzyaloshinskii−Moriya Interaction (DMI) at the Graphene (Gr)/Ferromagnetic (FM) interface is a crucial step to promote SO technology enabling the electrical control of the transport and manipulation of (topologically protected) magnetic structures.The partners of the consortium have already demonstrated the ability to tune the SOC by metal intercalation and the important magnetic interactions including the perpendicular anisotropy, the interlayer dipolar fields or the interfacial DMI by layer engineering, in order to control the chirality of the magnetic domain walls and skyrmions, to detect electrically nanometer spin textures, to realize graphene mediated antiferromagnetic coupling (AFC) between FMs, and finally to engineer ferroelectricity for application in various flavours of ferroelectric memories.SOgraphMEM project aims to i) functionalize the SOC induced parameters, ii) characterize, and iii) test the graphene based Spin-Orbitronic systems/devices operating at room temperature by exploiting the advantages of combining FM ultrathin films underneath of a Gr layer, non-magnetic films of heavy metals (HM), and ferroelectric (FE) compounds (doped-HfO2, HfZrO2). We aim at exploiting the polarization of the FE in order to ultimately realize voltage-controlled resistive and magnetic switching devices. We will adopt a specific methodology to fabricate the stacks, which will have the following sequence FE / Gr / FM / HM onto insulating oxides. In order to stabilize the spin textures, we will also explore the use of AFC through Gr in synthetic antiferromagnetic (SAF) stack, i.e. FM2 / Gr / FM1.Different issues related to the electric field control of the interface-SOC-induced effects will be addressed: a) effects of the electric field onto the surface magnetic anisotropy and DMI, b) spin orbit torque (SOT) and spin transfer torque (STT) characteristics as function of an external magnetic and/or electric field, c) magnetic anisotropy of the induced magnetic moment in Gr.In view of practical applications, SOgraphMEM will open the way for the development of the next generation of spintronics devices beyond the Moore’s law, exhibiting low power, high velocity and large density, as well as efficient spin injection/detection.