Tunable topological hybrid materials via interface- and topology-engineered heterostructures

非技术描述：一种名为拓扑材料的新材料已经出现，它具有制造奇异的电子和量子设备的诱人特性。然而，这些性质受到缺陷的影响，这些缺陷阻碍了它们的潜在应用。该项目提供了一种新的方法来控制这些缺陷，并通过结合各种拓扑和非拓扑材料来开发可调杂化材料。更多具有优异或新性质的拓扑材料的出现，为量子计算和量子信息技术的发展提供了条件。该项目包括与许多其他研究人员的密切合作。从代表性不足的群体招募的博士后、研究生和本科生将接受培训和指导，以成为薄膜量子材料领域的下一代领导者。有计划地向当地小学推广活动，向广大社区培养科学和科学家的积极形象。技术描述：拓扑学在过去十年中作为一种新的电子材料分类范式出现，并发现了包括拓扑绝缘体和拓扑半金属在内的一系列拓扑材料。然而，作为自掺杂的本征缺陷长期以来一直是达到拓扑态的量子制度的主要障碍。近年来，这位首席研究员已经证明，这些缺陷中的大多数都源于接口，而通过适当的接口工程方案，这些缺陷中的大多数都可以消除。此外，还表明，某些拓扑材料的拓扑结构和其他临界性质可以通过固体混合和数字分层等薄膜工程方案来连续调整。然而，到目前为止所研究的大多数拓扑材料都是热力学定义的化合物。该项目旨在将拓扑材料的边界扩展到热力学极限之外，通过开发一系列具有各种薄膜工程方案的可调人工拓扑材料，如固体混合、数字分层、尺寸约束和界面缺陷工程，来探索新的拓扑现象。通过结合各种界面和拓扑工程方案，该项目沿着两个方向开发可调的拓扑杂化材料和探索尚未发现的拓扑量子效应：1.可调的人工拓扑材料和2.可调的界面拓扑超导体。这些材料允许探索动力学和热力学驱动的增长图景之间的边界，并发现拓扑、磁性和超导相交的新物理，包括最小磁性Weyl半金属、高温量子反常霍尔相、轴子绝缘体和界面超导。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。

Nontechnical Description:A new class of materials called topological materials has emerged with attractive properties for making exotic electronic and quantum devices. However, these properties are affected by defects which hamper their potential applications. This project provides a novel way of controlling these defects as well as developing tunable hybrid materials by combining a variety of topological and non-topological materials. Availability of more topological materials with superior or new properties enables development of technology for quantum computing and quantum information. The project includes close collaboration with many other researchers. Postdocs, graduate and undergraduate students recruited from underrepresented groups receive training and mentoring to become next generation leaders in thin film quantum materials. Planned outreach activities to local elementary schools foster positive images of science and scientists to the broad community.Technical Description:Topology has emerged as a new paradigm of classifying electronic materials over the past decade, and a series of topological materials including topological insulators and topological semimetals have been discovered. However, native defects, working as self-dopants, have long been a major hurdle in the way to reaching the quantum regime of the topological states. In recent years, the principle investigator has demonstrated that majority of these defects originate from interfaces and with proper interface-engineering schemes, most of these defects can be eliminated. Furthermore, it was shown that topology and other critical properties of certain topological materials can be continuously tuned through thin film engineering schemes such as solid mixing and digital layering. However, most of the topological materials investigated so far have been thermodynamically-defined compounds. This project seeks to extend the boundary of topological materials beyond the thermodynamic limit and search for new topological phenomena by developing a series of tunable artificial topological materials with various thin film engineering schemes such as solid-mixing, digital-layering, dimensional confinement, and interfacial defect engineering. By combining a variety of interface and topology-engineering schemes, this project develops tunable topological hybrid materials and explore yet-to-be-discovered topological quantum effects, along two Thrusts: 1. Tunable artificial topological materials and 2. Tunable interfacial topological superconductors. These materials allow exploring the boundaries between kinetically vs thermodynamically-driven growth landscapes and uncovering new physics where topology, magnetism and superconductivity meet, including and beyond minimal magnetic Weyl semimetals, high temperature quantum anomalous Hall phase, axion insulators, and interfacial superconductivity.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.