Emergent Collective Phenomena in Transition Metal Oxides

* 技术摘要 * 该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。复合氧化物提供了许多机会来研究电子之间强相互作用产生的新的电子、磁性和结构现象，如高Tc超导电性、量子自旋液态和磁电性。理解它们的微观机制以及探索它们丰富的相图对凝聚态物理学提出了巨大的挑战。这个个人研究者奖支持一个项目，研究几种典型的过渡金属氧化物，以解决一些基本问题，特别是关注相关的自由度，如自旋，电荷和晶格，如何耦合，以诱导上述复杂的属性。特别感兴趣的是探索可能的新阶段和量子相变的量子和挫折磁铁，检查电子-声子耦合在高温超导体，并测试相互冲突的理论模型在磁性多铁性。将采用弹性/非弹性中子散射技术，直接探测原子长度尺度下固体的静态和动态特性。本科生和研究生将在美国的几个国际顶级研究机构学习，欧洲和日本的晶体生长和中子散射测量。* * 该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。电子是携带电荷和自旋（磁矩）的基本粒子。固体中的电子丰富，当满足某些条件时，电子可以相互强烈地相互作用，产生新的现象。强关联电子系统中集体行为的著名例子是导致磁悬浮的超导性和允许同时控制磁性和电子性质的多铁性，两者都具有潜在的革命性工业应用。本项目将通过研究几种典型的复合氧化物来解决这些现象的关键问题。这一结果将促进我们对自旋、电荷和晶格是如何相互关联从而导致这种效应的理解。这项研究将为如何更好地设计未来技术应用的性能提供重要信息。本科生和研究生将在几个国际顶级研究机构接受最先进的晶体生长和表征技术的培训，并将有机会发展自己的国际研究网络。

****TECHNICAL ABSTRACT****This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Complex oxides provide numerous opportunities to study novel electronic, magnetic, and struc-tural phenomena that emerge out of strong interactions between electrons, such as high Tc su-perconductivity, quantum spin liquid states, and magneto-electricity. Understanding their under-lying microscopic mechanisms as well as exploring their rich phase diagrams poses grand challenges in condensed matter physics. This individual investigator award supports a project to study several exemplary transition metal oxides to address some fundamental questions, especially focusing on how the relevant degrees of freedom, such as spin, charge, and lattice, are coupled to induce the aforementioned complex properties. Of particular interest are the exploration of possible new phases and quantum phase transitions in quantum and frustrated magnets, examination of electron-phonon coupling in high Tc superconductors, and testing conflicting theoretical models in magnetic multiferroics. Elastic/inelastic neutron scattering techniques that directly probe static and dynamic properties of solid at the atomic length scale will be employed. Undergraduate and graduate students will spend time at several internationally top research institutes in the U.S., Europe, and Japan for crystal growth and neutron scattering measurements.****NON-TECHNICAL ABSTRACT****This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). An electron is an elementary particle that carries electric charge and spin (magnetic moment). Abundant in a solid, electrons can interact strongly with each other to bring about novel phenomena when certain conditions are met. Well-known examples of the collective behaviors in strongly correlated electron systems are superconductivity that leads to magnetic levitation and multiferroicity that allows one to control magnetic and electronic properties simultaneously, both of which have potential revolutionary industrial applications. This project will address key issues regarding these phenomena by investigating several exemplary complex oxides. The outcome will advance our understanding of how the spin, charge and crystal lattice are correlated to cause such effects. The research will provide important information on how to better engineer the properties for future technical applications. Undergraduate and graduate students will be trained in state-of-the-art crystal growth and characterization techniques at several international top research institutes, and will have opportunities to develop their own international research network.