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

• 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

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.

分子和固体中相对论效应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，大多数有趣的物理现象都依赖于强电子关联的存在。然而，当进入较重的过渡金属元素（即 4d 和 5d 系统）时，随着 d 轨道变得越来越延伸，电子-电子相互作用逐渐减弱。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，例如铱酸盐和锇酸盐，当这些相互作用在相同的能量尺度上相遇时，会出现有趣的情况。随后出现的晶体场效应、局域多重态物理、自旋轨道耦合和位点间跳跃之间的相互作用，为相关电子材料的研究打开了一个新的窗口，提供了新型的相关基态和激发。更奇特的例子是虹膜中可能的拓扑态，例如拓扑莫特绝缘体，以及长期以来寻求的具有键依赖性自旋-自旋相互作用的基塔耶夫模型的可能实现。该项目的目标是提供更深入的理论见解有趣的 5d 氧化物（例如铱酸盐和锇酸盐）的基本电子结构和磁性。为此，我们将建立在波函数电子结构理论的概念和计算工具的基础上，特别是现代量子化学的相关多参考方法和最近开发的固态嵌入技术。我们的工作将为固体中相关效应和自旋轨道相互作用的相互作用提供新的视角。

项目成果

Mechanism of basal-plane antiferromagnetism in the spin-orbit driven iridate Ba2IrO4

自旋轨道驱动铱酸盐Ba2IrO4基面反铁磁性机制

• DOI: 10.1103/physrevx.4.021051
• 发表时间: 2014
• 期刊: Physical Review X
• 影响因子: 12.5
• 作者: V. M. Katukuri; V. Yushankhai; L. Siurakshina; J. van den Brink; L. Hozoi; I. Rousochatzakis
• 通讯作者: I. Rousochatzakis

Kitaev interactions between j = 1/2 moments in honeycomb Na2IrO3 are large and ferromagnetic: insights from ab initio quantum chemistry calculations

蜂窝状 Na2IrO3 中 j = 1/2 矩之间的 Kitaev 相互作用很大并且具有铁磁性：从头算量子化学计算的见解

• DOI: 10.1088/1367-2630/16/1/013056
• 发表时间: 2013-12-28
• 期刊: New Journal of Physics
• 影响因子: 3.3
• 作者: V. Katukuri;S. Nishimoto;V. Yushankhai;V. Yushankhai;A. Stoyanova;H. K;pal;pal;Sungkyun Choi;R. Coldea;I. Rousochatzakis;L. Hozoi;J. Brink
• 通讯作者: J. Brink

Kitaev exchange and field-induced quantum spin-liquid states in honeycomb α-RuCl3

蜂窝α-RuCl3 中基塔耶夫交换和场致量子自旋液态

• DOI: 10.1038/srep37925
• 发表时间: 2016-11-30
• 期刊: Scientific Reports
• 影响因子: 4.6
• 作者: Yadav R;Bogdanov NA;Katukuri VM;Nishimoto S;van den Brink J;Hozoi L
• 通讯作者: Hozoi L

Strongly frustrated triangular spin lattice emerging from triplet dimer formation in honeycomb Li2IrO3

蜂窝状 Li2IrO3 中三重态二聚体形成产生的强烈受挫三角自旋晶格

• DOI: 10.1038/ncomms10273
• 发表时间: 2016-01-18
• 期刊: Nature Communications
• 影响因子: 16.6
• 作者: Nishimoto S;Katukuri VM;Yushankhai V;Stoll H;Rößler UK;Hozoi L;Rousochatzakis I;van den Brink J
• 通讯作者: van den Brink J

Orbital reconstruction in nonpolar tetravalent transition-metal oxide layers

非极性四价过渡金属氧化物层的轨道重建

• DOI: 10.1038/ncomms8306
• 发表时间: 2015-06-24
• 期刊: Nature Communications
• 影响因子: 16.6
• 作者: Bogdanov, Nikolay A.;Katukuri, Vamshi M.;Romhanyi, Judit;Yushankhai, Viktor;Kataev, Vladislav;Buechner, Bernd;van den Brink, Jeroen;Hozoi, Liviu
• 通讯作者: Hozoi, Liviu