Spin Orbit functionalized GRAPHene for resistive-magnetic MEMories

对高密度、低功耗和快速自旋逻辑器件的需求要求材料的组合，这些材料可以提供具有长自旋寿命和自旋传播的合适的自旋传输通道，以及可以作为快速信息载体的拓扑稳定的自旋织构。通过利用特定多层结构中电子的自旋和动量自由度(自旋-轨道电子学，SO)，可以满足自旋电子技术在未来几年发展的这些先决条件。此外，在石墨烯(Gr)/铁磁(Fm)界面上发现了强的dzyaloshinskii−moriya相互作用(Dmi)，这是促进SO技术的关键一步，使得能够对(拓扑保护的)磁结构的输运和操纵进行电控制。该联盟的合作伙伴已经展示了通过金属嵌入和重要的磁相互作用(包括垂直各向异性、层间偶极场或界面dmi)通过层工程来调节SOC的能力，以控制磁畴壁和Skyrmions的手性，检测电纳米自旋织构，实现石墨烯和Fm之间的反铁磁耦合(AFC)SOgraph MEM项目的目标是i)功能化SOC诱导参数，ii)表征和iii)测试基于石墨烯的自旋轨道电子学系统/器件，通过在Gr层下结合FM超薄膜、重金属非磁性薄膜(HM)和铁电(FE)化合物(掺杂HfO2，HfZrO2)的优势来测试在室温下运行的石墨烯基自旋轨道电子学系统/器件。我们的目标是利用FE的极化来最终实现压控阻性和磁开关器件。我们将采用一种特定的方法来制造堆栈，其将在绝缘氧化物上具有如下顺序：FE/Gr/FM/HM。为了稳定自旋织构，我们还将探索AFC到Gr在合成反铁磁(SAF)堆栈中的应用，即FM2/Gr/FM1。我们将讨论与界面SOC诱导效应的电场控制有关的不同问题：a)电场对表面磁各向异性和DMI的影响，b)自旋轨道扭矩(SOT)和自旋转移扭矩(STT)特性作为外部磁场和/或电场的函数，c)Gr中感应磁矩的磁各向异性。从实际应用来看，SOgraph MEM将为下一代超越摩尔定律的自旋电子器件的开发开辟道路，展示低功率、高速度和大密度，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.