Spin Injection and Manipulation in Graphene-based Spintronics Devices

该项目旨在开发一个综合的实验和教育框架，以了解基于石墨烯的自旋电子器件中的动态自旋泵浦、自旋注入和纯自旋流的产生。与新加坡国立大学石墨烯研究中心合作，制定了一系列实验和理论研究活动的战略。这项拟议研究的目标是开发用于信息处理的纳米级设备，在这种设备中，完全可以控制磁状态，而不需要依赖电荷电流。在新兴的自旋电子学技术中，纯自旋流的产生和控制正变得至关重要。石墨烯的独特性质提供了纯自旋电流器件的优势，成为下一代信息处理和存储硬件的优秀候选者。拟议的研究将与一系列教育和培训活动相结合，包括在基础物理和应用物理方面对研究生进行培训，并从国际合作中获得经验。PIs致力于让未被充分代表的基团参与所有水平的研究活动。该项目提出了一系列实验和理论研究活动，以了解在使用动态自旋泵浦和自旋霍尔效应(SHE)的石墨烯自旋电子器件中纯自旋电流的注入和控制。其目标是开发用于信息处理的纳米级设备，在这种设备中，可以在没有净电荷电流直接干预的情况下完全控制磁状态。提出的装置将利用石墨烯的独特性质，允许产生和操纵纯自旋电流，以控制装置的磁状态，这是基于非栅极元件的自旋转移扭矩装置所不可能做到的。该项目的具体目标是：a)了解不同结构条件(剥离、化学气相沉积生长和氢化石墨烯)和不同界面配置(Fm/Gr和Fm/MgO/Gr)下从铁磁体(FM)到单层和多层石墨烯(Gr)的动态自旋泵浦；b)了解不同结构条件下单层和多层石墨烯中的SHE，并研究其作为栅极电压的函数的行为；以及，c)开发基于石墨烯的可门控纯自旋电流阀，该阀同时使用动态自旋泵浦和SHE，以允许有效地控制设备的磁状态，并探索其在下一代低功率高速MRAM、信息处理和存储设备中的潜在应用。

This project aims at developing an integrated experimental and educational framework for understanding of dynamical spin pumping, spin injection, and generation of pure spin currents in graphene-based spintronics devices. A series of experimental and theoretical research activities have been strategized in collaboration with the Graphene Research Centre at the National University of Singapore. The goal of the proposed research is to develop nanoscale devices for information processing where a complete control of the magnetic state is possible without relying on charge currents. Within emerging spintronics technologies, the generation and control of pure spin currents is becoming of paramount relevance. The unique property of graphene offers the advantage of pure spin current devices as preeminent candidate for the next generation of information processing and storage hardware. The proposed research will be integrated with a series of educational and training activities, including training of graduate students at the interface of fundamental and applied physics, and gain experience from international collaboration. The PIs are committed to involving underrepresented groups in the research activities at all levels.The project proposes a series of experimental and theoretical research activities for the understanding of injection and control of pure spin currents in graphene-based spintronic devices that uses dynamical spin pumping and the spin-Hall effect (SHE). The goal is to develop nanoscale devices for information processing where a complete control of the magnetic state is possible without the direct intervention of net charge currents. The proposed devices will make use of the unique properties of graphene to allow generation and manipulation of pure spin currents for controlling the magnetic state of the device that not possible with spin transfer torque devices based on non-gateable elements. The specific objectives of the project are to: a) understand dynamical spin pumping from a ferromagnet (FM) into single-layer and multi-layer graphene (Gr) under different structural conditions exfoliated, chemical vapor deposition grown, and hydrogenated graphene) and for different interfacial configurations (FM/Gr and FM/MgO/Gr); b) understand the SHE in single-layer and multi-layer graphene under different structural conditions and study its behavior as a function of the gate voltage; and, c) develop graphene-based gateable pure spin current valves that uses both dynamical spin pumping and SHE to allow for an efficient control of magnetic state of the devices and explore their potential applications for next generationlow-power high-speed MRAM, information processing and storage devices.