Spin Orbitronics: Interfacial Design of Spintronic Materials and Devices

近几十年来，计算和通信技术的显著进步是基于传统电子技术，而传统电子技术的基本极限正在迅速接近。 为了满足未来低功耗、高性能存储器和逻辑器件的需求，迫切需要开发新的物理机制和先进的材料。 一个很有前途的方法是利用电子自旋自由度在一个范式广泛称为自旋电子学。 实现自旋电子学技术的关键是能够有效地操纵纳米器件中的电子自旋。 该研究项目旨在从根本上了解磁性和磁性材料之间界面上出现的令人兴奋的新现象，这些新现象提供了操纵电子自旋的强大新机制。 基础研究将通过使新型自旋电子器件实现超低功耗，高性能计算和大容量数据存储，从而对移动的计算和全球能源效率产生广泛的技术影响。 该计划将培养本科生和研究生在先进的纳米技术，并通过国际合作提供丰富。 研究，教育和推广是高度一体化的团队研究生与本科生，当地高中教师和代表性不足的学生。 将利用MITx/EdX在线教育平台开发和广泛传播教育媒体，包括教学实验室模块和课程材料。这项研究计划将提供一个非常规的电流引起的扭矩和手性自旋纹理，出现在铁磁异质结构与破坏反转对称性和强自旋轨道耦合的基本理解。 该计划旨在（1）定量和系统地表征铁磁体/重金属双层膜中的自旋轨道扭矩，以确定其对界面材料和结构的依赖性，（2）提供对强自旋轨道耦合存在下磁化切换和磁畴壁运动的机械理解，以及（3）建立优化自旋电子器件这些现象所需的材料设计原则。实验重点是过渡金属和合金，秩序远远高于室温，界面的重金属和氧化物的可接受的集成与传统的半导体制造工艺。 这些基础研究的智力价值包括对表面和界面磁性的重要新见解，纳米尺度系统中对称性破坏的量子力学效应，以及电荷和自旋自由度之间的耦合。 基础研究将带来革命性的新自旋存储器和逻辑器件功能，提供增强的性能和耐用性以及超低功耗要求。

The remarkable advances in computing and communications technologies in recent decades have been based on conventional electronics whose fundamental limits are rapidly being approached. In order to meet the demands for future low-power, high-performance memory and logic devices, new physical mechanisms and advanced materials that exploit them are urgently required. A promising approach is to harness the electron spin degree of freedom in a paradigm widely known as spintronics. The key to realizing spintronics technologies is the capability to efficiently manipulate the electron spin in nanoscale devices. This research program seeks a fundamental understanding of exciting new phenomena that emerge at interfaces between magnetic and nonmagnetic materials, which offer powerful new mechanisms to manipulate electron spins. The fundamental research will have broad technological impact by enabling new classes of spintronic devices for ultralow-power, high-performance computation and mass data storage, significantly impacting mobile computing and global energy efficiency. The program will train undergraduate and graduate students in advanced nanotechnologies, and provide enrichment through international collaborations. Research, education, and outreach are highly integrated by teaming graduate students with undergraduates, local high school teachers and underrepresented students. Educational media including instructional laboratory modules and course materials will be developed and disseminated broadly using the MITx/EdX online educational platform. This research program will provide a fundamental understanding of unconventional current-induced torques and chiral spin textures that arise in ultrathin ferromagnetic heterostructures with broken inversion symmetry and strong spin-orbit coupling. The program aims to (1) quantitatively and systematically characterize spin-orbit torques in ferromagnet/heavy metal bilayers to identify their dependence on interface materials and structure, (2) provide a mechanistic understanding of magnetization switching and magnetic domain wall motion in the presence of strong spin-orbit coupling, and (3) establish the materials design principles necessary to optimize these phenomena for spintronic devices. Experiments focus on transition metals and alloys that order well above room temperature, interfaced with nonmagnetic heavy metals and oxide dielectrics that are amenable to integration with conventional semiconductor fabrication processes. The intellectual merits of these fundamental studies include important new insights into surface and interface magnetism, the quantum-mechanical effects of broken symmetries in nanoscale systems, and coupling between the charge and spin degrees of freedom. The fundamental studies will lead to revolutionary new spin-based memory and logic device capabilities, offering enhanced performance and durability with ultralow power consumption requirements.