Unconventional electronic ground states and novel physical properties due to strong spin-orbit couplings and correlation effects in 5d oxides

由于 5d 氧化物中强自旋轨道耦合和相关效应，非常规电子基态和新颖的物理特性

基本信息

批准号：
233478970
负责人：
Dr. Liviu Hozoi
金额：
--
依托单位：
Institut für Theoretische Festkörperphysik
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2013
资助国家：
德国
起止时间：
2012-12-31 至 2015-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/233478970?language=en
关键词：
Unconventional electronic ground states novel

项目摘要

One of the most important consequences of relativistic effects in molecules and solids is the coupling of spin and orbital degrees of freedom. In 3d-metal oxides, the spin-orbit coupling is relatively weak and most of the intriguing physics rests on the presence of strong electron correlations. Electron-electron interactions turn nevertheless progressively weaker when going to heavier transition-metal elements, i.e., 4d and 5d systems, as the d orbitals become more and more extended. The relativistic spin-orbit coupling, on the other hand, follows the opposite trend: it increases progressively. In 5d-metal compounds, e.g., iridates and osmates, the interesting situation arises where these interactions meet on the same energy scale. The interplay between crystal-field effects, local multiplet physics, spin-orbit couplings, and intersite hopping that subsequently emerges has opened up a new window of interest in correlated electronic materials, offering novel types of correlated ground states and excitations. The more exotic examples are possible topological states in iridates, such as the topological Mott insulator, and the possible realization of the long-sought Kitaev model with bond-dependent spin-spin interactions.The goal of this project is providing deeper theoretical insight into the basic electronic structure and magnetic properties of intriguing 5d oxide compounds such as the iridates and osmates. For this purpose, we will build on concepts and computational tools from wavefunction electronic-structure theory, in particular, correlated multireference methods from modern quantum chemistry and recently developed solid-state embedding techniques. Our work shall foster new perspectives over the interplay of correlation effects and spin-orbit interactions in solids.

相对论效应在分子和固体中最重要的后果之一是自旋和轨道自由度的耦合。在3D金属氧化物中，自旋轨道耦合相对较弱，大多数有趣的物理均取决于存在强电子相关性。当D轨道变得越来越扩展时，电子 - 电子相互作用逐渐变弱，即4D和5D系统，即4D和5D系统。另一方面，相对论自旋轨道耦合遵循相反的趋势：它逐渐增加。在5D金属化合物中，例如虹膜和渗透液中，这些相互作用以相同的能量尺度相遇的有趣情况。晶体场效应，局部多重物理，自旋轨道耦合和跨站点跳跃之间的相互作用，随后出现了，已经为相关的电子材料开辟了一个新的兴趣窗口，提供了新型的相关类型的基础状态和兴奋。更异国情调的例子是源自虹膜的拓扑状态，例如拓扑莫特绝缘子，以及具有依赖键依赖性的自旋旋转相互作用的长期追求的基塔夫模型。该项目的目的是为基本的电子结构和诸如Irived 5D氧化物复合物的基本电子结构和磁性的基本电子结构和磁性磁性提供更深入的理论见解。为此，我们将基于波函数电子结构理论的概念和计算工具，特别是从现代量子化学和最近开发的固态嵌入技术中相关的多次多次方法。我们的工作应促进有关固体中相关效应和自旋轨道相互作用的相互作用的新观点。