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

非技术描述：一种被称为拓扑材料的新材料已经出现，它具有制造奇异电子和量子器件的吸引人的特性。然而，这些特性受到缺陷的影响，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，以及通过结合各种拓扑和非拓扑材料来开发可调谐的混合材料。更多具有优越或新特性的拓扑材料的可用性使量子计算和量子信息技术的发展成为可能。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中招募的博士后、研究生和本科生接受培训和指导，成为薄膜量子材料领域的下一代领导者。计划在当地小学开展外展活动，向广大社区树立科学和科学家的正面形象。技术描述：在过去的十年中，拓扑学已经成为一种新的电子材料分类范式，包括拓扑绝缘体和拓扑半金属在内的一系列拓扑材料已经被发现。然而，原生缺陷作为自掺杂剂，长期以来一直是实现拓扑态量子态的主要障碍。近年来，主要研究者已经证明了这些缺陷中的大多数来自接口，并且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，研究还表明，某些拓扑材料的拓扑结构和其他关键性质可以通过固体混合和数字分层等薄膜工程方案连续调谐。然而，迄今为止研究的大多数拓扑材料都是热力学定义的化合物。本项目通过固体混合、数字分层、尺寸限制和界面缺陷工程等多种薄膜工程方案，开发一系列可调人工拓扑材料，将拓扑材料的边界扩展到热力学极限之外，寻找新的拓扑现象。通过结合各种界面和拓扑工程方案，本项目沿着两个方向开发可调拓扑混合材料并探索尚未发现的拓扑量子效应：1。1 .可调人工拓扑材料；可调谐界面拓扑超导体。这些材料允许探索动力学与热力学驱动的生长景观之间的边界，并发现拓扑，磁性和超导性相遇的新物理，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性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.