Novel States in Spin-Orbit-Coupled and Correlated Materials

非技术摘要：现代凝聚态物理学研究已经产生了具有基本特性的新型材料，这些材料支撑了大量尖端技术。现在人们普遍认为，新材料是技术进步的关键，谁发现了新材料，谁就控制了未来的科学和技术。过渡金属氧化物在基础科学和应用科学领域都引起了极大的兴趣。 然而，几十年来，压倒性的平衡的努力集中在三维元素（如铁，铜等）。以及它们的化合物;较重的4D-和5D-元素（例如钌，铱等，其构成元素周期表中所列d-元素的三分之二）及其化合物直到最近才在很大程度上被忽视。主要研究人员试图发现含有4d和/或5d元素的新材料，并了解它们如何为发现新物理学和最终新器件范例提供广泛的机会。该项目还为所有参与的学生提供严格的培训，重点是合成和表征技术，涵盖了主要研究者实验室中可用的广泛材料和实验探针。 技术摘要：由自旋轨道相互作用驱动的物理是当代凝聚态物理学中最重要的课题之一。由于自旋-轨道相互作用与现场库仑和其他相关相互作用相当，因此它在驱动复杂行为的竞争相互作用和在其他材料中未观察到的奇异状态之间建立了独特的平衡。该项目包括系统地努力阐明自旋轨道耦合和相关材料中的新现象的物理学，以及对具有奇异基态的新材料的严格搜索。该项目侧重于以下领域：（1）高压和强磁场下的新现象，（2）铱酸盐和铼酸盐中绝缘带隙和磁跃迁之间的不寻常相关性，（3）铱酸盐中的奇异金属态和超导态，（4）具有“中等强度”自旋轨道相互作用和其他竞争能量的莫特绝缘体，（5）单晶合成和新材料的寻找。首席研究员是少数几个主要先驱者之一，他们发起了对铱酸盐的开创性研究，并在此之前，对铱酸盐进行了研究，并拥有全面的设施和单晶合成以及对温度，磁场，压力和掺杂的结构，运输，磁性，热和介电性质的广泛研究的成熟专业知识。

Non-technical Abstract:Modern condensed matter physics research has produced novel materials with fundamental properties that underpin a remarkable number of cutting-edge technologies. It is now generally accepted that novel materials are necessary for critical advances in technologies and whoever discovers novel materials generally controls the science and technology of the future. Transition metal oxides have attracted enormous interest within both the basic and applied science communities. However, for many decades, the overwhelming balance of effort was focused on the 3d-elements (such as iron, copper, etc.) and their compounds; the heavier 4d- and 5d-elements (such as ruthenium, iridium, etc., which constitute two thirds of the d-elements listed in the Periodic Table) and their compounds have been largely ignored until recently. The principal investigator seeks to discover novel materials containing 4d- and/or 5d-elements and understand how they offer wide-ranging opportunities for the discovery of new physics and, ultimately, new device paradigms. This project also provides rigorous training to all students involved, focusing on synthesis and characterization techniques covering a broad spectrum of materials and experimental probes available in the principal investigator's laboratory. Technical Abstract:Physics driven by spin-orbit interactions is among the most important topics in contemporary condensed matter physics. Since the spin-orbit interaction is comparable to the on-site Coulomb and other relevant interactions, it creates a unique balance between competing interactions that drive complex behaviors and exotic states not observed in other materials. The project encompasses a systematic effort to elucidate physics of novel phenomena in spin-orbit-coupled and correlated materials and a rigorous search for new materials having exotic ground states. This project focuses on the following areas: (1) Novel phenomena at high pressures and high magnetic fields, (2) Unusual correlations between the insulating gap and magnetic transition in iridates and ruthenates, (3) Exotic metallic and superconducting states in iridates, (4) Mott insulators with "intermediate-strength" spin-orbit interaction and other competing energies, and (5) Single-crystal synthesis and search for novel materials. The principal investigator is one of a few key pioneers who have initiated seminal studies on iridates and, before that, ruthenates, and has comprehensive facilities and proven expertise for single-crystal synthesis and wide-ranging studies of structural, transport, magnetic, thermal and dielectric properties as functions of temperature, magnetic field, pressure and doping.