Spin-orbit coupling and dimensionality at the heart of quantum magnetism of heavy transition metal oxides

重过渡金属氧化物量子磁性核心的自旋轨道耦合和维数

• 批准号: EP/W00562X/1
• 负责人: Devashibhai Adroja
• 金额: $ 48.29万
• 依托单位: Science and Technology Facilities Council
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FW00562X%2F1
• 关键词: Spin; orbit; coupling; dimensionality; heart

This proposal is focused on the study of quantum materials with competing interactions. Measurements of the various quantum-mechanical phases provide the most direct manifestation of the underlying abstract physics, such as quantum spin liquid, topological behaviour and quantum entanglement. The in-depth experimental and theoretical investigations of emergent phenomena of the candidate quantum materials have been serving as a major theme of recent condensed matter physics research. Understanding the complex magnetic interactions in these novel quantum materials is crucial for the development of fundamental science in the form of modern theory of higher d transition metal oxides, as well as for the strong foundation of alternative pathways towards the design of new and exotic materials and functional devices, which hold true promise for future generation of technological applications. The investigations on the novel 5d Iridates and 4d rhodates reveal a burgeoning list of theoretical proposals as well as predictions of unusual states, such as Jeff half Mott-insulating state, the quantum spin liquid phase, Kitaev quantum magnetism, unconventional superconductivity, Weyl semimetals, correlated topological insulators, etc., which are indeed truly remarkable and stimulating. The physics of iridates, ruthenates and rhodates clearly warrants serious intellectual challenges both theoretically and experimentally, and hence, in this proposal we focus on design, synthesis and characterisation of the new candidate quantum materials within 4d Rh/Ru- and 5d Ir-based oxides. Quantum spin liquid (QSL) is a novel state of quantum magnetism where long range magnetic order is suppressed due to strong quantum fluctuations down to the lowest temperature. The gapless QSLs exhibit long-range quantum-entanglement and fractionalised spin excitations named as Majorana Fermions. Such fractionalised spin excitations are different from conventional magnons observed in compounds with long-range magnetic ordering. The present proposal is therefore aimed to investigate the exotic and unconventional magnetic ground states of iridates, ruthenates and rhodates within a variety of crystal structures and lattice geometries by implementing detailed experimental study (both laboratory based and state-of-art neutron, muon and x-ray synchrotron based advanced measurements) and ab-initio electronic structure calculations. These in-depth investigations will help in understanding the importance of various competing interactions, e.g. spin-orbit interaction, on-site Coulomb U, crystal field, Hund's coupling, hopping and electronic bandwidth. The nature of the extraordinary structural sensitivity of quantum materials also calls for extraordinarily high-quality single crystals and we are planning to synthesise such single crystals using UCL crystal growth lab at Harwell and investigate them using various central facilities.

该提案的重点是研究具有竞争相互作用的量子材料。各种量子力学相的测量提供了底层抽象物理的最直接表现，例如量子自旋液体、拓扑行为和量子纠缠。对候选量子材料的涌现现象进行深入的实验和理论研究一直是近年来凝聚态物理研究的一个主题。了解这些新型量子材料中复杂的磁相互作用对于以高维过渡金属氧化物现代理论的形式发展基础科学至关重要，也为设计新型奇异材料和功能器件的替代途径奠定了坚实的基础，这为下一代技术应用带来了真正的希望。对新颖的5d Iridates和4d rhodates的研究揭示了一系列新兴的理论建议以及对不寻常状态的预测，例如杰夫半莫特绝缘态、量子自旋液相、基塔耶夫量子磁性、非常规超导性、韦尔半金属、相关拓扑绝缘体等，这确实是令人瞩目和令人兴奋的。铱酸盐、钌酸盐和铑酸盐的物理学显然需要在理论和实验上面临严峻的智力挑战，因此，在本提案中，我们重点关注 4d Rh/Ru 和 5d Ir 基氧化物中新候选量子材料的设计、合成和表征。量子自旋液体（QSL）是一种新颖的量子磁性状态，由于低至最低温度的强烈量子涨落，长程磁序受到抑制。无间隙 QSL 表现出长程量子纠缠和分段自旋激发，称为马约拉纳费米子。这种分段自旋激发不同于在具有长程磁有序的化合物中观察到的传统磁振子。因此，本提案旨在通过实施详细的实验研究（基于实验室和基于最先进的中子、μ介子和X射线同步加速器的高级测量）和从头算电子结构计算，研究各种晶体结构和晶格几何结构中铱酸盐、钌酸盐和罗得酸盐的奇异和非常规磁基态。这些深入的调查将有助于理解各种竞争性相互作用的重要性，例如自旋轨道相互作用、现场库仑 U、晶体场、洪德耦合、跳跃和电子带宽。量子材料非凡的结构敏感性的本质也需要极高品质的单晶，我们计划使用位于哈韦尔的伦敦大学学院晶体生长实验室合成此类单晶，并使用各种中央设施对其进行研究。

项目成果

Superconducting Gap Structure of the Noncentrosymmetric Topological Superconductor Candidate HfRuP

• DOI: 10.3390/magnetochemistry9050135
• 发表时间: 2023-05
• 期刊: Magnetochemistry
• 影响因子: 2.7
• 作者: D. Das;D. Adroja;R. Tripathi;Z. Guguchia;F. Hotz;H. Luetkens;Zhijun Wang;Dayu Yan;Huiqian Luo;Youguo Shi

Magnetic and Magnetoelectric Materials

磁性和磁电材料

• DOI: 10.3390/magnetochemistry10020008
• 发表时间: 2024
• 期刊: Magnetochemistry
• 影响因子: 2.7
• 作者: Adroja D

Thermal conductivity, thermoelectric power and Mössbauer investigations on atiferromagnetic CeFe1.7Ir0.3Al10

反铁磁 CeFe1.7Ir0.3Al10 的热导率、热电势和穆斯堡尔研究

• DOI: 10.1016/j.jmmm.2022.169370
• 发表时间: 2022
• 期刊: Journal of Magnetism and Magnetic Materials
• 影响因子: 2.7
• 作者: Anand V

Metamagnetism and crystal-field splitting in pseudohexagonal CeRh 3 Si 2

赝六方 CeRh 3 Si 2 中的超磁性和晶体场分裂

• DOI: 10.1103/physrevb.105.125119
• 发表时间: 2022
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Amorese A