Topological Materials and Electron Correlations

凝聚态物质与材料理论和凝聚态物理计划共同为该奖项提供支持。非技术性总结在过去的几十年里，“拓扑学”的数学概念已经成为材料科学中的一个新的组织原则，它可以确定，例如，固体表面是金属还是电绝缘。 拓扑是指当材料局部扰动时保持不变的全局属性。 拓扑材料属性保持稳健，例如，对局部缺陷或污垢的存在。 拓扑材料中电子之间的相互作用可能很弱，也可能很强，而且，由于用于研究这两类电子的方法不同，两个科学家团体一直在平行的轨道上工作。 该领域的广泛性要求社区之间进行互动。该研讨会旨在汇集这两个社区的顶级专家，以突出每个领域的最新成就，并为主题之间的相互对话提供一个论坛。 莱斯大学莱斯量子材料中心将举办为期两天的研讨会，汇集来自地球仪各地的顶级专家和初级研究人员，他们通过实验探索候选材料，从理论上发展拓扑材料的现象学，并了解强相关性的作用。本次研讨会的主要特点是将对拓扑材料感兴趣的弱相关和强相关社区聚集在一起。 这将解决理解和探索拓扑物质和强关联之间的交叉点的迫切需要。技术摘要弱关联电子中的拓扑物质近年来取得了重大进展。例子包括“高阶”拓扑绝缘体的发现及其潜在的实验实现，磁有序材料中的外尔半金属，以及磁振子拓扑状态的探索。 与此同时，在过去的几年里，在探索强关联系统的电子拓扑结构方面取得了迅速的进展。例子包括在重费米子材料中发现强相关的外尔半金属，以及在近藤绝缘体和铁基超导体中寻找拓扑态特征的进展。在大多数情况下，这两个方向一直在发展，串扰非常有限。现在是促进两族之间积极对话的特别适当的时机。该研讨会旨在通过汇集来自弱相关性和强相关性社区的对拓扑材料感兴趣的关键参与者来实现这一目标。为了增加串扰的机会，它将采用各种材料，包括涉及sp电子的弱相互作用系统，基于d-和f-电子的强相关化合物，包括石墨烯层，液体3 He和超冷原子的工程结构。会议主题的选择既考虑到了近年来的兴奋程度和进展速度，也考虑到了相互促进的可能性。经发言者许可，会议结束后，将汇编演讲幻灯片，并以PDF格式从会议网站上下载。幻灯片将包括小组讨论的成果摘要。该奖项反映了NSF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。

The Condensed Matter and Materials Theory and Condensed Matter Physics Programs jointly contribute support to this award.Non-Technical SummaryOver the last couple of decades, the mathematical concept of "topology" has emerged as a new organizing principle in the science of materials, one that can determine, for example, whether the surface of a solid is metallic or electrically insulating. Topology refers to global properties that stay the same when a material is perturbed locally. Topological materials properties remain robust, for instance, against the presence of local imperfections or dirt. The interactions between electrons in topological materials can be weak or strong, and, because the methods used to study these two classes differ, two communities of scientists have been working on parallel tracks. The breadth of the field calls for interactions among the communities. This workshop aims to bring together top experts from these two communities to highlight the recent achievements in each area and to provide a forum for cross-talk between the subjects. Rice University's Rice Center for Quantum Materials will host a two-day workshop on this topic, bringing together top experts and junior researchers from around the globe who probe experimentally candidate materials, develop theoretically the phenomenology of topological materials, and understand the role of strong correlations. The key distinguishing feature of this workshop will be to bring together the weakly and strongly correlated communities interested in topological materials. This will address an acute need to understand and explore the intersection between topological matter and strong correlations.Technical SummaryTopological matter in weakly correlated electrons has seen major advances in recent years. Examples include the discovery of "higher-order" topological insulators and their potential experimental realization, Weyl semimetals in magnetically ordered materials, and explorations of topological states of magnons. Meanwhile, rapid progress has taken place during the last couple of years in exploring electronic topology of strongly correlated systems. Examples include the discovery of strongly correlated Weyl semimetals in heavy-Fermion materials and progress in the search for signatures of topological states in Kondo insulators and iron-based superconductors. For the most part, the two directions have been developing with very limited crosstalk. Now is a particularly opportune time to foster active dialogue between the two communities. The workshop aims to realize this goal by bringing together key players interested in topological materials from the communities of both weak and strong correlations. To enhance the opportunities for crosstalk, it will feature a variety of materials, ranging from weakly interacting systems involving sp-electrons, strongly correlated compounds based on d- and f- electrons, engineered structures including graphene layers, liquid 3He and ultracold atoms. The topics have been chosen with a view to both the level of excitement and the pace of advances that have been made in recent years, as well as by the potential for cross fertilization.With permission from the speakers, the slides from the talks will be compiled and made available for download in pdf form from the meeting website following the conclusion of the meeting. The slides will include the summary outcomes of the group discussions. The participants will be encouraged to use these as a springboard for graduate education about these problems at their institutions.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.