CAREER: Novel Magnetic Phases in Spin Orbit Coupled Correlated Electron Systems

非技术摘要：磁铁的实际应用可以追溯到至少两千年前指南针的发明，并在今天广泛使用的磁性信息编码和存储中蓬勃发展。这些应用是基于包含称为3D过渡金属的特定元素的材料。然而，更多类型的磁相被预测存在，并被提出用于应用。一个奇特的例子是量子自旋液体，其中的自旋方向永远不会对齐，总是波动，即使是在尽可能低的温度下也是如此。这可以被用来制造量子计算机。另一个例子是磁性多极相，其中原子磁铁具有比简单的箭头更复杂的多极结构，可以用于超高速电子设备。这项工作的重点是一类氧化物，并将导致非传统的磁相和控制它们的方法在未来的应用。PI与密歇根大学历史博物馆合作开展K-12教育推广活动，如开发桌面演示、建立研究站和参与科学交流计划，她指导本科生和研究生，目的是鼓励他们广泛参与研究和培养下一代科学家。技术摘要：这个项目针对的是一类新的材料--5D过渡金属氧化物中的新型磁性相，其中电子关联和自旋轨道耦合在可比的能量尺度上共存。具体地说，该项目由三项密切相关的研究工作组成：(1)开发和利用一套对称敏感的光学技术，如磁光克尔效应、非线性光学光谱和拉曼光谱，来探测自旋轨道耦合相关电子材料中磁相的基态和激发；(2)研究这些磁相在化学替代和直流磁场等静态控制下的演化，以驱动量子相变；(3)探索利用现代飞秒脉冲激光的电磁辐射对这些磁相进行动态控制，并实现热不可达的隐藏相。在这种新的相互作用机制中发现新的磁相有助于理解具有共同的强电子关联和强自旋轨道耦合的物理学，而对这些新磁相的成功控制指导了新材料的合理设计，以实现长期追求的量子相和新器件。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。

Non-technical Abstract: The practical applications of magnets date back at least two thousand years to the invention of the compass, and thrive nowadays in the widely used magnetic information coding and storage. These applications are based on materials containing specific elements called 3d transition metals. However, many more types of magnetic phases are predicted to exist and proposed for applications. One exotic example is the quantum spin liquid, where the spins directions are never aligned and always fluctuating, even down to the lowest possible temperature. This could be exploited to make a quantum computer. Another example is the magnetic multipolar phase, where the atomic magnets have a more complex multipole structure than just a simple arrow, that could be used for ultrahigh-speed electronics. This work focuses on a class of oxides, and will lead to unconventional magnetic phases and ways to control them for future applications. The PI collaborates with the University of Michigan Museum of History to perform K-12 education outreach, such as developing table-top demonstrations, setting up research stations, and participating in science communication programs, and she mentors undergraduate and graduate students with twin aims of encouraging broad participation in research and preparing the next generation of scientists. Technical Abstract: This project is directed at novel magnetic phases in a new class of materials, 5d transition metal oxides, where electron correlations and spin orbit coupling coexist at comparable energy scales. Specifically, the project consists of three closely related research efforts: (1) developing and utilizing a set of symmetry sensitive optical techniques, magneto-optical Kerr effect, nonlinear optical spectroscopy, and Raman spectroscopy, to probe both ground states and excitation of the magnetic phases in spin orbit coupled correlated electron materials; (2) investigating the evolution of these magnetic phases under static controls such as chemical substitution and DC magnetic field, in order to drive quantum phase transitions; (3) exploring dynamic control over these magnetic phases using electromagnetic radiation from modern femtosecond pulsed lasers, and realize thermally inaccessible hidden phases. The discovery of novel magnetic phases in this new interaction regime sheds light on the understanding of physics that has in common strong electron correlations and strong spin orbit coupling, and the successful control over these new magnetic phases guides rational design of new materials for realizing long sought-after quantum phases and novel devices.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.