NSF/DMR-BSF: Spatially Resolved Probes of Magnetism at Oxide Interfaces

非技术摘要：一些最引人注目的发现与磁性的存在和性质有关，非磁性界面上的磁性仍然是现代物理学中最伟大的未解之谜之一。实验证据表明，磁性与超导性共存，并且在室温下存在磁性。这个项目试图提供对这种意想不到的现象的理解。这项研究需要精通各种领域，包括物理、材料科学和纳米工程，这使得它对刚开始的研究生和本科生具有挑战性和回报。学生还可以在国际研究环境中获得宝贵的培训和经验：该研究项目是通过与以色列魏茨曼研究所的一个研究团队的国际合作而成为可能的，并向学生提供科学和文化方面的知识。技术摘要：钛酸锶和铝酸镧这两种绝缘氧化物之间的界面呈现出令人难以置信的丰富的涌现行为。一些最引人注目的发现与磁性的存在和性质有关，磁性在低温下与超导性共存，并受到界面上移动电子密度的强烈影响。使用一套结合高空间和时间分辨率的探针，研究了关于（非磁性）氧化物界面磁性的起源和性质的基本问题。该项目旨在增加对氧化物中耦合相的理解，极大地有利于整个氧化物社区。该研究的重点是发展对氧化物界面磁性起源的微观理解，特别强调局域和非局域电子的作用，否则这些电子将局限于这些界面。这项研究结合了低温下超灵敏的磁性探针和利用导电原子显微镜光刻技术制造电子纳米结构的能力。各种互补成像技术被用来揭示氧化物界面的磁性，包括磁力显微镜、时间分辨克尔旋转和尖端超导量子干涉装置显微镜。这种独特的技术组合，由美国和以色列之间的国际合作实现，能够为有关这一非凡物质系统的最重要的杰出物理问题提供新的见解。

Nontechnical abstract:Some of the most remarkable discoveries are related to the existence and nature of magnetism, and magnetism at a non-magnetic interface remains one of the greatest outstanding mysteries of modern physics. Experimental evidence has revealed magnetism coexisting with superconductivity, and the existence of magnetism at room temperature. This project seeks to provide understanding of such unexpected phenomena. The research requires proficiency in a variety of areas including physics, materials science, and nanoscale engineering, making it challenging and rewarding for beginning graduate and undergraduate students. Students also receive valuable training and experience in an international research setting: this research project is made possible by an international collaboration with a research team from the Weizmann Institute in Israel and exposes students both scientifically and culturally.Technical abstract:The interface between two insulating oxides, strontium titanate and lanthanum aluminate, exhibits an incredibly rich palette of emergent behavior. Some of the most remarkable discoveries have related to the existence and nature of magnetism, which coexists at low temperature with superconductivity, and is strongly influenced by the density of mobile electrons at the interface. Fundamental questions about the origin and nature of magnetism at (non-magnetic) oxide interfaces are investigated using a suite of probes that combine high spatial and temporal resolution. This project seeks an increased understanding of coupled phases in oxides, greatly benefiting the oxide community as a whole. The research focuses on developing a microscopic understanding of the origin of magnetism at oxide interfaces, with a particular emphasis on the role of both localized and delocalized electrons that are otherwise confined to these interfaces. This research combines ultrasensitive probes of magnetism at low temperature with the ability to create electronic nanostructures using conductive-atomic fore microscope lithography. A variety of complementary imaging techniques are employed to reveal magnetic properties at the oxide interface, including magnetic force microscopy , time resolved Kerr rotation, and superconducting-quantum-interference-device-on-a-tip microscopy. This unique combination of techniques, made possible by an international collaboration between the United States and Israel, is able to provide new insights into the most important outstanding physics questions concerning this remarkable material system.