CAREER: Designing Topological States in van der Waals Structures

非技术摘要：随着电子设备尺寸的缩小，它们的整体性能正在下降。为了进一步提高未来电子器件的性能和缩小尺寸，需要探索基于量子现象的新材料。其中一类特别有希望的量子材料是拓扑绝缘体，它的特征是体电不导电，在其边界处具有高导电性的电子态。本程序主要对只有几个原子厚度的二维(2D)拓扑绝缘体的性质进行实验研究。这些材料的性能可以通过堆积不同材料组成的单分子膜来实现，并可以通过施加电场来控制。该项目的研究方面伴随着一项广泛的教育和外联计划，旨在为研究生和本科生在工业和学术界的成功职业生涯做好准备，并通过为帕萨迪纳联合学区的高中生和教师进行讲座和实验室参观来帮助教育公众有关量子科学和纳米技术的知识。此外，该项目的所有成果将通过国内和国际会议和期刊文章的演讲以及面向广大受众的公开博客帖子和教育视频广泛传播。技术摘要：该职业奖支持对范德华材料和异质结构中物质的拓扑相的实验探索。由于其固有的二维特性，这些超薄材料可以通过量子输运测量和扫描探针显微镜的紧密结合来进行研究。该研究小组将专注于将扫描隧道显微镜获得的边缘态的局部结构和电子性质与各种实验设置中的整体输运特征相关联。这种方法将允许对相关的后向散射机制以及螺旋边缘的自旋极化和自旋弛豫有新的见解。该团队还将探索将2D拓扑范德华材料与超导体耦合的前景，以创建一维和零维的拓扑保护超导量子态。该项目将为整合研究、教育和推广提供充足的机会。特别是，作为这一项目的一部分，首席调查员将为普通公众开发讲座，并为本科生和研究生改进课程课程，涵盖量子科学和纳米技术的最新主题。研究成果将通过国内和国际会议和期刊文章的演讲以及面向广大受众的公开博客文章和教育视频广泛传播。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Non-Technical Abstract: As electronic devices shrink in size, their overall performance is degrading. Novel materials based on quantum phenomena need to be explored in order to further boost the performance and reduce size of future electronic devices. One particular promising class of such quantum materials are topological insulators which are characterized by electrically non-conductive bulk alongside with a highly conductive electronic state at its boundaries. This program focuses on experimental research of the properties in two-dimensional (2D) topological insulators that are only a few atoms thick. The properties of these materials can be engineered by stacking monolayers with different material composition and controlled by applying electric fields. The research aspects of this project are accompanied by an extensive educational and outreach plan aimed to prepare graduate and undergraduate students for successful careers in industry and academia as well as help educate general public about quantum science and nanotechnology through lectures and lab tours for high-school students and teachers from the Pasadena Unified School District. Moreover, all results from this project will be broadly disseminated through the talks at national and international conferences and journal articles as well as in publicly accessible blog posts and educational videos targeting broad audience.Technical Abstract:This CAREER award supports experimental exploration of topological phases of matter in van der Waals materials and hetero-structures. Due to their intrinsic 2D character, these ultrathin materials can be studied by closely integrated combination of quantum transport measurements and scanning probe microscopy. The research team will focus on correlating local structural and electronic properties of the edge states obtained using scanning tunneling microscopy with the overall transport signatures in variety of experimental settings. This approach will allow for novel insights into the relevant backscattering mechanisms as well as into the spin polarization and spin relaxation of the helical edges. The team will also explore prospects of coupling 2D topological van der Waals materials to superconductors in order to create topologically protected superconducting quantum states in one and zero dimensions. This project will offer ample opportunities for integrating research, education and outreach. In particular, as a part of this project, the principle investigator will develop lectures for the general public and enhance course curriculum for undergraduate and graduate students that will cover the most recent topics in quantum science and nanotechnology. The research results will be broadly disseminated through the talks at national and international conferences and journal articles as well as in publicly accessible blog posts and educational videos targeting broad audience.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.