Beyond Conventional Methods: Chemical Routes to Dope Topological Insulator Nanostructures and Two-Dimensional Materials Magnetically

超越传统方法：磁性掺杂拓扑绝缘体纳米结构和二维材料的化学路线

• 批准号: 1402600
• 负责人: Judy Cha
• 金额: $ 39.54万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1402600&HistoricalAwards=false
• 关键词: Beyond; Conventional; Methods; Chemical; Routes

**Non-Technical Description**This award from the Condensed Matter Physics Program of the Division of Materials Research supports Yale University with a project to develop novel chemical doping methods for topological insulator nanostructures to alleviate current materials challenges facing the field. Topological insulators possess exotic conducting surface states that can be used as information carriers that do not generate wasted heat. Thus topological insulators can replace current copper interconnects, resulting in great reduction of energy consumption for the society. This research will bring the realization of topological insulators as alternative interconnects one step closer to reality. Additionally, the methods can be successfully applied to two-dimensional, layered semiconductors to create dilute magnetic semiconductors for much broader impact for the society. Dilute magnetic semiconductors are widely studied for spintronics applications. The work contributes to the training of skilled technical workforce and contains elements for new course development on nanomaterials. In addition, the project promotes the participation of underrepresented groups.**Technical Description**This award from the Condensed Matter Physics Program of the Division of Materials Research to Yale University supports a project to develop novel chemical methods to dope topological insulator nanomaterials with magnetic impurities, and to open a band gap in the topological surface states. Two chemical methods are investigated. The first method employs intercalation of magnetic atoms, ions, and molecules at the Van der Waals gap of layered topological insulators. The second method employs surface modification of topological insulator nanostructures with molecular spins. These methods exhibit significant advantages over conventional doping methods: 1) higher concentration of magnetic dopants, 2) no clustering of magnetic dopants, 3) spatial ordering of magnetic dopants into anti-ferromagnetism or ferromagnetism, and 4) broad applicability to other two-dimensional layered materials. Nanodevices will be fabricated to measure magnetotransport at low temperature to characterize the doping. The successful outcome of this research will lead to a materials platform in which fundamental condensed matter physics phenomena can be explored to advance knowledge in band gap in topological surface states, in topological magneto-electric effect, and quantum anomalous Hall effect. It is anticipated that the methodology developed in this project can be general. The research involves training undergraduate students to conduct research independently, developing new components for a nanotechnology course, and dissemination of knowledge through publications and conference presentations and outreach..

**非技术描述**该奖项来自材料研究部凝聚态物理项目，支持耶鲁大学开展一个项目，开发用于拓扑绝缘体纳米结构的新型化学掺杂方法，以缓解该领域当前面临的材料挑战。拓扑绝缘体具有奇异的导电表面态，可用作不产生废热的信息载体。 因此，拓扑绝缘体可以取代当前的铜互连，从而大大减少社会的能源消耗。这项研究将使拓扑绝缘体作为替代互连的实现更接近现实。此外，这些方法可以成功应用于二维层状半导体，以制造稀磁半导体，从而对社会产生更广泛的影响。稀磁半导体在自旋电子学应用中得到了广泛研究。这项工作有助于培训熟练的技术人员，并包含纳米材料新课程开发的要素。此外，该项目还促进了代表性不足的群体的参与。**技术说明**该奖项由耶鲁大学材料研究部凝聚态物理项目授予，用于支持开发新颖的化学方法以磁性掺杂拓扑绝缘体纳米材料的项目杂质，并在拓扑表面态中打开带隙。研究了两种化学方法。第一种方法是在层状拓扑绝缘体的范德华间隙处插入磁性原子、离子和分子。第二种方法利用分子自旋对拓扑绝缘体纳米结构进行表面修饰。这些方法比传统的掺杂方法表现出显着的优势：1）磁性掺杂剂浓度更高，2）磁性掺杂剂不会聚集，3）磁性掺杂剂空间排序为反铁磁性或铁磁性，4）对其他二维材料的广泛适用性分层材料。将制造纳米器件来测量低温下的磁输运以表征掺杂。这项研究的成功成果将建立一个材料平台，在该平台上可以探索基本的凝聚态物理现象，以增进对拓扑表面态带隙、拓扑磁电效应和量子反常霍尔效应的认识。预计该项目中开发的方法可以具有通用性。该研究包括培训本科生独立进行研究、开发纳米技术课程的新组件以及通过出版物和会议演示和外展传播知识。