Dynamical Spin Pumping in Graphene-based Spintronics Devices

本项目旨在开发一个综合实验和教育框架，用于研究、理解和传播动态自旋泵、自旋注入以及石墨烯基自旋电子学器件中纯自旋电流的产生和识别。为此，PI和他的研究生将于2013年夏天在新加坡国立大学（NUS）花两个月的时间，在那里他们将开发片上集成FMR/传输设备，通过直接测量石墨烯层中产生的纯自旋电流产生的逆自旋霍尔效应（ISHE）电势，来研究基于石墨烯的系统中的动态自旋注入。特别是，基于石墨烯的铁磁/非磁（FM/NM）双层层将与微cpw集成在单个芯片上。比较不同石墨烯（Gr）基FM/NM双层（例如Py/Gr）之间的FMR线宽展宽和ISHE电压，将有助于深入了解Py-石墨烯界面上发生的自旋弛豫机制，并有助于确定石墨烯基自旋电子器件在新兴技术中的潜力。由此产生的技术专长将在返回美国后被移植，以利用中佛罗里达大学（UCF）现有的纳米制造设施，获得将合作扩展到未来的新设备。该项目定义了中佛罗里达大学（UCF）和新加坡国立大学（NUS）石墨烯研究中心之间的国际合作，以理解、产生和控制石墨烯基自旋电子器件中的纯自旋电流。其中纯二维碳原子层（即石墨烯）的独特电子特性可能会提供新颖的功能，这可能会在广泛扩展的技术方面产生突破性的结果，例如磁随机存取存储设备（MRAM）。提出的研究可能会导致基于石墨烯的自旋电子学器件实现新的应用，并可能对社会产生直接影响。考虑到欧盟最近宣布向一个由众多欧洲研究小组组成的网络拨款10亿欧元，专门用于石墨烯的研究，拟议的研究计划是及时的。在这方面，美国PI与世界公认的石墨烯研究中心之间提出的国际合作将使这种材料的研究能够独立进行，并提高UCF在这种高度竞争和激烈的情况下的知名度。此外，参与该项目的研究生将直接受益于他在最先进的石墨烯研究中心之一的学习。2013年夏天在新加坡国立大学合作访问期间获得的知识将被移植到UCF，以便在随后的几年中继续拟议的国际合作，从而使一些在学生群体中代表性较低的部分的本科生和研究生受益匪浅。

This project aims to develop an integrated experimental and educational framework for the study, understanding, and dissemination of dynamical spin pumping, spin injection and the generation and identification of pure spin currents in graphene-based spintronics devices. For this, the PI and his graduate student will spend two months at National University of Singapore (NUS) during the Summer of 2013, where they will develop on-chip integrated FMR/transport devices to enable the study of dynamical spin injection in graphene-based systems by means of the direct measurement of the inverse spin Hall-effect (ISHE) electric potential generated as a result of the pure spin currents generated in the graphene layer. In particular, graphene-based ferromagnet/non-magnetic (FM/NM) bilayers will be integrated together with µ-CPWs on a single chip. The comparison of the FMR linewidth broadening and the ISHE voltage between different graphene(Gr)-based FM/NM bilayers (e.g. Py/Gr) will provide insight on the spin relaxation mechanisms taking place at the Py-graphene interface, and help identifying the potential of graphene-based spintronic devices in emerging technologies. The resulting technical expertise will be transplanted upon return to the US, to make use of the existing nanofabrication facilities at University of Central Florida (UCF), to obtain new devices for extending the collaboration into the future.The project defines the creation of an international collaboration between University of Central Flor-ida (UCF) and the Graphene Research Centre at the National University of Singapore (NUS) for the understanding, generation and control of pure spin currents in graphene-based spintronic devices, where the unique electronic properties of a purely two-dimensional layer of carbon atoms (i.e. gra-phene) will likely provide novel functionalities which could result in groundbreaking in regards to widely extended technologies, such as in magnetic random access memory devices (MRAM). The proposed studies may lead to graphene-based spintronics devices enabling novel applications, with a possible immediate impact in society. The proposed research plan is timely considering that the Eu-ropean Union has recently announced one billion euros for research dedicated exclusively on gra-phene, granted to a network formed by numerous European research groups. In this regard, the pro-posed international collaboration between the US PI and a worldwide recognized graphene research center will enable studies of this material that could not be pursued independently, and enhance UCF visibility in such a highly competitive and fervent scenario. In addition, the graduate student involved in this project will directly benefit from his stay in one of the most advanced centers for re-search in graphene. The knowledge acquired during the collaboration visit at NUS in summer 2013 will be transplanted into UCF allowing the continuation of the proposed international collaboration in subsequent years, from which a number of undergraduate and graduate students with a high representation of underrepresented sections of the student population will greatly benefit.