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

研究内部交换场和自旋过滤影响下的二维系统和表面态

• 批准号: 1207469
• 负责人: Jagadeesh Moodera
• 金额: $ 56万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-06-01 至 2017-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1207469&HistoricalAwards=false
• 关键词: Investigating; Two; Dimensional; Systems; Surface

****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.

****技术摘要****本实验项目旨在研究在内部交换场和自旋滤波的影响下，拓扑绝缘体（TI）和石墨烯等二维系统和表面态。本研究利用磁性绝缘体薄膜和多层叠层的邻近感应铁磁性，研究具有定制界面的狄拉克电子系统中的铁磁性秩序。从理论上预测，自旋子带是分裂的，并将极大地改变可由电场控制的自旋输运。我们将研究这类系统中的电荷和自旋输运行为。该项目还将寻找马约拉纳费米子，理论上预测存在于p + ip超导层的交换分裂表面状态，具有强自旋-轨道耦合：所需的这些纳米级结构将被研究。除了丰富的物理学之外，人们相信这些研究可以作为未来重要的量子信息技术的基石。各个层次的学生（包括HS学生）和博士后将参与这项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****本项目研究二维新型量子系统，不仅带来科学进步，而且在未来量子信息技术中具有潜力。服从相对论量子力学的两种新发现的材料系统（石墨烯和拓扑绝缘体）具有非凡的特性，当磁力被引入其中时更是如此。该项目将研究后一种情况下的电和磁行为，理论上预测会显示出深刻的性质变化，开辟新的量子物理学领域。当这在实验中得到验证时，按照这个项目的计划，它有望成为未来重要的节能和经济上可行的量子器件的基石，如基于非易失性自旋的存储器和逻辑器件。材料表征工具，包括那些在国家设施将提高他们的能力。在美国和国外都将有科学合作。学生（含高中生）和博士后参与本实验项目。他们将在包括国家实验室在内的纳米级最先进的科学领域接受培训，为美国未来的先进科学技术奠定科学基础。

项目成果

Spatially modulated magnetic structure of EuS due to the tetragonal domain structure of SrTiO3

由于 SrTiO3 的四方磁畴结构，EuS 的空间调制磁结构

• DOI: 10.1103/physrevmaterials.1.074406
• 发表时间: 2017
• 期刊: Physical Review Materials
• 影响因子: 3.4
• 作者: Rosenberg, Aaron J.;Katmis, Ferhat;Kirtley, John R.;Gedik, Nuh;Moodera, Jagadeesh S.;Moler, Kathryn A.
• 通讯作者: Moler, Kathryn A.

Dirac-electron-mediated magnetic proximity effect in topological insulator/magnetic insulator heterostructures

• DOI: 10.1103/physrevb.96.201301
• 发表时间: 2017-06
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Mingda Li;Qichen Song;Weiwei Zhao;J. Garlow;Te-Huan Liu;Lijun Wu;Yimei Zhu;J. Moodera;M. Chan-M.-Cha