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****该实验项目旨在研究二维系统和表面状态，例如拓扑绝缘体（TI）和石墨烯，在内部交换场和自旋过滤的影响下。这项研究是关于这些狄拉克电子系统中的铁磁顺序，利用磁绝缘子薄膜和多层堆栈具有接近性诱导的铁磁性，并带有量身定制的接口。从理论上讲，旋转子频带被拆分，并且会大大改变可以通过电场控制的自旋传输。将研究此类系统中的电荷和旋转运输行为。该项目还将寻求Majorana fermions，从理论上预测，将在P + IP超导层的交换表面状态下与强旋轨耦合：所需的纳米级结构。除了丰富的物理学外，人们认为这些研究还可以作为建立重要的未来量子信息技术的基础。各个级别的学生（包括HS学生）和博士后将参加这项尖端的基本物理研究。他们将学习纳米级的最先进的界面特征技术，包括国家实验室以及纳米技术。****非技术摘要****该项目调查了二维新颖的量子系统，不仅会带来科学进步，而且还可以在未来的量子信息技术中进行潜在的潜在量子技术。遵守相对论量子力学的两个新发现的材料系统（石墨烯和拓扑绝缘子）具有非凡的特性，而当其中引入磁性时，更是如此。该项目将研究后一种情况下的电气和磁性行为，从理论上讲，将显示出属性的深刻变化。按照该项目的计划，在实验中对此进行了验证时，预计它将作为对重要的未来能源有效且经济上可行的量子设备（例如非挥发性旋转的内存和逻辑设备）的基础。材料表征工具，包括国家设施的工具将提高其能力。美国和国外都将进行科学合作。学生（包括高中生）和博士后参加了这个实验项目。他们将接受纳米级最先进的科学培训，包括在国家实验室，建立美国先进科学技术的未来科学基础。

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