DMREF Collaborative Research: Establishing the Platform of Quasi-one-dimensional Topological Insulators with Emergent Functionalities

非技术描述：将拓扑学的概念应用于固态系统彻底改变了我们对量子现象和材料的理解，并激发了电子，原子，光子，机械和声学系统中新功能的设计。例如，拓扑绝缘体（TI）是一类在本体中电绝缘但具有导电表面状态的材料。在对称性和拓扑结构的保护下，这些表面态不受杂质的影响，因此能够从不完美的界面制造出近乎完美的器件，这对传统和量子信息技术都很重要。然而，在实现其全部潜力之前，必须解决当前TI材料中存在的许多关键挑战。该项目旨在通过关注一类新材料（具有新兴功能的准一维（准1D）TI）来克服这些挑战。将建立理论建模和预测，材料合成和表征的迭代循环，以发现不同的准一维TI家族，并探索其独特的拓扑现象和功能特性。该项目的成功将为下一代信息技术和可持续能源解决方案的拓扑量子计算和低功耗自旋电子学的实现带来光明。主要的教育活动将通过开展公共宣传、培训研究生和本科生、增加代表性不足的群体的参与、为物理学和材料科学提供一个新的面貌（两名女性在该团队中担任领导职务）以及向技术社区和公众开放研究和教育成果等方式融入研究活动。技术描述：到目前为止，大多数识别的TI要么是强粘结的散装材料或层状货车德瓦尔斯材料。尽管他们的丰富性，根本的障碍和限制存在于展示的决定性的属性，实现充分的承诺，TI，如表面狄拉克锥的限制，一个特定的分裂平面，弱的电子相互作用和有限的可调性。值得注意的是，准一维结构有望克服这些挑战。该项目的目标包括准一维TI候选物的设计和优化，合成和表征，通过应变和温度调节拓扑相变，以及在准一维材料的原子级薄层中寻找二维TI。通过在理论和计算、材料合成、自旋和角度分辨光电子能谱、纳米纤维、量子输运以及中子和X射线散射方面的互补专业知识和共同努力，该项目有望导致发现新的TI、相和现象，控制拓扑转变，该奖项反映了NSF的法定使命，并通过使用基金会的知识产权进行评估，被认为值得支持。优点和更广泛的影响审查标准。

Non-technical Description: Applying the concept of topology to solid state systems has revolutionized our understanding of quantum phenomena and materials, and inspired the design of new functionalities in electronic, atomic, photonic, mechanical, and acoustic systems. For instance, topological insulators (TIs) are a class of materials that are electrically insulating in the bulk, but host conductive surface states. Protected by symmetry and topology, these surface states are immune to impurities and thus enable making near-perfect devices from imperfect interfaces, which are important for both conventional and quantum information technology. However, there exist a number of critical challenges in current TI materials that must be addressed before realizing their full potential. This project aims at overcoming these challenges by focusing on a new class of materials, quasi-one-dimensional (quasi-1D) TIs with emergent functionalities. An iterative loop of theoretical modeling and prediction, material synthesis, and characterization will be established to discover different families of quasi-1D TIs and explore their unique properties for topological phenomena and functionalities. The project's success will shed light on the realization of topological quantum computing and low-power spintronics for next-generation information technology and sustainable energy solutions. Major educational activities will be integrated into the research activities by performing public outreach, training graduate and undergraduate students, increasing participation of under-represented groups, providing a new face to physics and materials science with two women in leadership positions on this team, and offering open access to research and education outputs to the technical community and general public.Technical Description: To date, most of the identified TIs are either strongly bonded bulk materials or layered van der Waals materials. Despite their richness, fundamental obstacles and limitations exist in exhibiting the decisive properties and realizing the full promise of TIs, such as the restriction of surface Dirac cones to a specific cleavage plane, weak electronic interactions and limited tunability. Remarkably, a quasi-1D structure promises to overcome these challenges. The goals of this project include design and optimization of quasi-1D TI candidates, synthesis and characterization, tuning topological phase transitions by strain and temperature, and seeking 2D TIs in atomically thin layers of quasi-1D materials. Through complementary expertise and concerted efforts on theory and computation, material synthesis, spin- and angle-resolved photoemission spectroscopy, nanofabrication, quantum transport, and neutron and x-ray scattering, the project is expected to lead to the discovery of novel TIs, phases and phenomena, controlling topological transitions, and enabling superior functionalities and fostering quantum technologies.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.