CAREER: GHz imaging of strongly correlated and topological phenomena in moire materials

凝聚态物理学的一个主要目标是在新兴的量子材料中发现新的电子态。一个突出的例子是迅速扩大的拓扑绝缘体类别，其特征是包围绝缘内部的导电边缘。该项目揭示了二维（2D）材料中相关性和拓扑结构相互作用可能产生的奇异现象，并利用这些新相来构建下一代量子器件。我们方法的关键是使用一种新型低温成像技术，该技术检测高频导电边缘电流的独特指纹，并在空间上将它们与材料内部的琐碎状态解开。2D材料中新兴的拓扑状态可能在未来被利用来实现新的量子技术，包括非常强大的量子计算形式，其中环境噪声被强烈抑制。为了培养下一代科学家和工程师，该项目还开发了一个新的量子材料和器件教学模块，为学生提供跨学科的工具箱，涵盖材料和器件制备，低温环境中的测量，数据分析和技术写作技能。为了整合研究和推广，首席研究员的目标是组织一个以科学为主题的公共艺术展览，展示量子材料的显微镜作为一个令人兴奋的科学探索的新前沿。技术摘要：本项目的目的是调查集体现象的微观性质所产生的相互作用和拓扑结构的相互作用在货车德瓦尔斯（vdW）异质结构和磁性拓扑绝缘体。 通过将微波阻抗显微镜（MIM）的前沿推向超低温，本研究致力于检测磁性拓扑绝缘体中等离子体激元激发的独特特征，并构建沿着边缘耗散的显微图像。基于材料前沿的最新发展，互补推力通过调整层与静电环境之间的角旋转来关注vdW异质结构中的工程相关拓扑状态。特别是，该项目重点研究了扭曲双层MoTe 2中的莫尔超晶格，其中窄带被预测会产生一系列多体状态，包括量子反常霍尔和反铁磁绝缘体。这些实验利用电子输运和微波成像方法来构建有序态的综合相图，揭示关键的破坏机制。这项研究为新兴量子材料中拓扑状态的GHz表征奠定了基础;它通过快速表征薄膜，多域系统和设备中的手性边缘状态来补充合成界的材料发现工作。 在未来，这种毫开尔文成像能力可能会被用于量子计算应用的设备平台中的拓扑状态的本地读出。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。

Nontechnical abstract: A major thrust of condensed matter physics concerns the discovery of new electronic states in emerging quantum materials. A prominent example is the rapidly expanding class of topological insulators, which are characterized by conductive edges that enclose an insulating interior. This project sheds light on exotic phenomena that can arise from the interplay of correlations and topology in two-dimensional (2D) materials and harnesses these novel phases to build the next generation of quantum devices. The key to our approach is use of a novel low temperature imaging technique, which detects the unique fingerprint of the conducting edge currents at high frequencies and spatially disentangles them from trivial states in the interior of the material. Emerging topological states in 2D materials could potentially be harnessed in the future to enable new quantum technologies, including exceptionally robust forms of quantum computing in which environmental noise is strongly suppressed. To train the next generation of scientists and engineers, this project also develops a new Quantum Materials and Devices teaching module, which equips students with an interdisciplinary toolbox spanning materials and device preparation, measurements in a cryogenic environment, data analysis, and technical writing skills. To integrate research and outreach, the principal investigator aims to organize a science-themed public art exhibit, which presents the microscopy of quantum materials as an exciting new frontier for scientific exploration.Technical abstract: The aim of this project is to investigate the microscopic nature of collective phenomena arising from the interplay of interactions and topology in van der Waals (vdW) heterostructures and magnetic topological insulators. By pushing the frontiers of microwave impedance microscopy (MIM) to ultra-low temperatures, this research strives to detect the unique signature of plasmonic excitations in magnetic topological insulators and construct a microscopic picture of dissipation along the edge. Building upon recent developments on the materials front, a complementary thrust focuses on engineering correlated topological states in vdW heterostructures by tuning the angular rotation between layers and the electrostatic environment. In particular, the project features a focused investigation of Moire superlattices in twisted bi-layer MoTe2, in which narrow bands are predicted to give rise to a family of many-body states, including quantum anomalous Hall and antiferromagnetic insulators. These experiments utilize electronic transport and microwave imaging methods to construct a comprehensive phase diagram of ordered states, shedding light on the key symmetry-breaking mechanisms. This research builds the foundation for GHz characterization of topological states in emerging quantum materials; it complements the materials discovery effort in the synthesis community by enabling fast characterization of chiral edge states in thin films, multi-domain systems, and devices. In the future, this milliKelvin imaging capability could potentially be used for local readout of topological states in device platforms for quantum computing applications.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.