Investigating Two-Dimensional Systems and Surface States Under the Influence of an Internal Exchange Field and Spin-Filtering

* 技术概要 * 本实验项目旨在研究拓扑绝缘体（TI）和石墨烯等的二维系统和内部交换场和自旋过滤影响下的表面状态。本研究利用磁性绝缘体薄膜和多层堆叠的邻近感生铁磁性，在这些狄拉克电子系统中的铁磁秩序，与定制的接口。理论上预测，自旋子带被分裂，并将显著改变可以由电场控制的自旋输运。在这样的系统中的电荷和自旋输运行为将被研究。该项目还将寻找马约拉纳费米子，理论上预测存在于具有强自旋轨道耦合的p + ip超导层的交换分裂表面态中：将研究这些所需的纳米结构。除了丰富的物理学之外，人们认为这些研究可以作为未来重要的量子信息技术的基石。各级学生（包括HS学生）和博士后将参与这一前沿的基础物理研究。他们将学习最先进的纳米级界面表征技术，包括在国家实验室，以及纳米技术。非技术摘要 * 本项目研究二维新量子系统，不仅带来科学进步，而且还为他们在未来的量子信息技术的潜力。这两种新发现的材料系统（石墨烯和拓扑绝缘体）服从相对论量子力学，具有非凡的性能，当磁性引入其中时更是如此。该项目将研究后一种情况下的电磁行为，理论上预测将显示出深刻的性质变化，开辟新的量子物理学领域。当这一点在实验上得到验证时，正如本项目所计划的那样，它有望成为未来重要的节能和经济可行的量子器件（如非易失性自旋存储器和逻辑器件）的基石。材料表征工具，包括国家设施中的材料表征工具，将提高其能力。将在美国和国外进行科学合作。学生（包括高中生）和博士后参加这个实验项目。他们将接受纳米级最先进科学的培训，包括在国家实验室，为美国先进的科学和技术建立未来的科学基础。

****Technical ABstract****This experimental project aims at investigating two-dimensional systems and surface states such as in topological insulators (TI) and graphene under the influence of an internal exchange field and spin filtering. This investigation is about ferromagnetic order in these Dirac electron systems utilizing the proximity-induced ferromagnetism by magnetic insulator thin film and multilayer stacks, with tailored interfaces. It is theoretically predicted that the spin sub-bands are split and would dramatically alter the spin transport that can be controlled by an electric field. The charge and spin transport behavior in such systems will be studied. This project will also seek Majorana fermions, theoretically predicted to exist in exchange split surface state of p + ip superconducting layer with a strong spin-orbit coupling: nanoscale structures of these, needed, will be investigated. In addition to the rich physics, it is believed that these studies could serve as building blocks towards important future quantum information technologies. Students at all levels (including HS students) and postdocs will participate in this cutting-edge fundamental physics research. They will learn state-of-the-art interfacial characterization techniques at the nanoscale including at the national labs, as well as nanotechnology.****Non-Technical Abstract****This project investigates two dimensional novel quantum systems to bring about not only scientific advancement, but also for their potential in future quantum information technologies. The two newly discovered materials systems (graphene and topological insulators) obeying relativistic quantum mechanics have extraordinary properties, and even more so when magnetism is introduced in them. This project will investigate the electrical and magnetic behavior in the latter case, theoretically predicted to show profound change of properties opening up new quantum areas of physics to explore. When this is verified experimentally, as planned in this project, it is expected to serve as building blocks towards important future energy efficient and economically viable quantum devices such as nonvolatile spin based memory and logic devices. Materials characterization tools, including those at the national facilities will be advancing their capabilities. There will be scientific collaboration both within USA and abroad. Students (including high school students) and postdocs participate in this experimental project. They will be trained in the state-of-the-art science at nanoscale including at the national labs, building the future scientific base for advanced science and technology in USA.