CAREER: Exploring Nonlinear Electrodynamics from Topology and Correlation in Layered Quantum Materials

该奖项的全部或部分资金来自《2021年美国救援计划法案》(公法117-2)。非技术描述：材料对电场和磁场的响应决定了其功能及其在电子和光学设备中的用途。非线性过程允许有趣的现象被广泛应用。例如，光限幅材料在低光强时可以是透明的，但在高强度(且具有潜在危险)时是不透明的。这允许用户在正常情况下查看，同时保护他们免受伤害。非线性电磁材料可以满足人们对具有新功能和更高效率的设备日益增长的需求。这一职业项目旨在探索由新型二维量子材料中电子的量子性质产生的新形式的非线性电磁学。这种低维带来了新的量子限制效应，可以为信息和能源技术提供高效和可调的电子设备。PI将通过由层状2D材料制造超薄电子器件并研究其在低温下的非线性电磁响应来探索原子薄层状量子材料的物理。该项目紧密结合了以量子材料、物理和技术为中心的研究活动、学生指导、教育计划和推广倡议。首席研究员特别致力于通过提拔女性研究人员和通过倡议计划培养年轻而充满活力的后备力量来解决物理学中的性别不平等问题。该项目由材料研究部(DMR)的电子与光子材料(EPM)和凝聚态物质物理(CMP)计划联合资助。技术描述：非线性电磁响应是材料对外部电磁场的非线性响应现象。最近的进展揭示了非线性电磁响应与量子物质的拓扑和Berry曲率性质之间的深刻联系，导致了一个新兴的拓扑非线性电磁学领域。在这个新生的领域，有许多问题需要解决。例如，新拓扑态的特征非线性响应是什么，它们可以有多大？杂质和散射在这些过程中的作用是什么？库仑相互作用的作用是什么？我们能用这些反应来探测和操纵紧急阶段吗？这个职业项目旨在通过探索原子薄层状量子材料中的物理来回答这些问题，这些材料具有可控的费米能量、能带结构、对称性、拓扑和电子相互作用，通过静电选通、范德华堆积和层扭曲。研究人员开发了用这些材料制造超薄电子器件的创新制造方法，并在自制的宽带电磁激励多功能磁传输/光学冷冻系统中研究了它们的非线性电磁特性。将高度可调的非线性材料与宽带激励相结合，将允许探索以前无法在拓扑和相关材料中访问的机制。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。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). Nontechnical Description: How a material responds to electric and magnetic fields determines its functionality and its usefulness in electronic and optical devices. Nonlinear processes allow for interesting phenomena with widespread applications. For example, an optical limiting material can be transparent at low light intensity but opaque at high (and potentially hazardous) intensity. This allows a user to see under normal conditions while protecting them from injury. Nonlinear electromagnetic materials can address growing demands for devices with new functionality and higher efficiency. This CAREER project aims to explore new forms of nonlinear electromagnetism that arise from the quantum properties of electrons in novel two-dimensional quantum materials. The low dimensionality gives rise to new quantum confinement effects that can enable highly efficient and tunable electronic devices for information and energy technologies. The PI will explore the physics of atomically-thin layered quantum materials by fabricating ultrathin electronic devices from layered 2D materials and studying their nonlinear electromagnetic response at low temperatures. The project intimately integrates research activities, student mentoring, educational plans, and outreach initiatives centered around quantum materials, physics, and technology. The principal investigator is particularly dedicated to addressing gender inequality in physics by promoting female researchers and cultivating a young and vigorous force reserve through initiative programs. This project is jointly funded by the Electronic and Photonic Materials (EPM) and the Condensed Matter Physics (CMP) programs of the Division of Materials Research (DMR).Technical Description: Nonlinear electromagnetic responses are the phenomena where materials respond nonlinearly to external electromagnetic fields. Recent advances uncovered deep connections between nonlinear electromagnetic responses and topological and Berry curvature properties of quantum matter, leading to an emerging field of topological nonlinear electromagnetism. In this nascent field many questions need to be addressed. For instance, what are the signature nonlinear responses of new topological states and how large can they be? What is the role of impurities and scattering in those processes? What is the role of Coulomb interactions? Can we use those responses to probe and manipulate emergent phases? This CAREER project aims to answer those questions by exploring the physics in atomically-thin layered quantum materials with controllable Fermi energy, band structures, symmetry, topology and electron interactions through electrostatic gating, van der Waals stacking and layer twisting. The investigator develops innovative fabrication methods to create ultrathin electronic devices from those materials and investigates their nonlinear electromagnetic properties in a home-built multi-functional magneto-transport/optics cryo-system with broadband electromagnetic excitation. Combining highly-tunable nonlinear materials with broadband excitation will permit exploration of previously inaccessible regimes in topological and correlated materials.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.