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arXiv 2204.07591cond-mat.mtrl-scicond-mat.str-el
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蜂窝晶格中Kitaev极限和Ising极限之间调谐的首次演示

First demonstration of tuning between the Kitaev and Ising limits in a honeycomb lattice

Faranak Bahrami, Xiaodong Hu, Yonghua Du, Oleg I. Lebedev, Chennan Wang, Hubertus Luetkens, Gilberto Fabbris, Michael J. Graf, Daniel Haskel, Ying Ran, Fazel Tafti

备注：
22 pages, 4 figures
发表信息：
Sci. Adv. 8, eabl5671 (2022)
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摘要：

近年来，对$4d/5d$过渡金属体系中新的自旋轨道耦合态的观测引起了人们极大的兴趣。一个主要的例子是铱酸盐材料中的$J_{\text{eff}}=\frac{1}{2}$态和驱动Kitaev相互作用的$α$ -RuCl $_{3}$。在这里，通过调整自旋轨道相互作用（$λ_{\text{SOC}}$）和三角晶场分裂（$Δ_\text{T}$）之间的竞争，我们重组的自旋轨道波函数到一个新的$μ=\frac{1}{2}$状态，驱动伊辛相互作用。这是通过将Li $_{2}$ RhO $_{3}$转化为Ag $_{3}$ LiRh $_{2}$ O $_{6}$的局部化学反应完成的，导致后一种化合物中三角畸变增强和自旋轨道耦合减弱。利用微扰理论，我们给出了在Ag $_{3}$ LiRh $_{2}$ O $_{6}$中实现的极限$Δ_\text{T}\gg λ_{\text{SOC}}$的新$μ=\frac{1}{2}$态的显式表达式，它不同于在Li $_{2}$ RhO $_{3}$中实现的极限$λ_{\text{SOC}}\gg Δ_\text{T}$的传统$J_\text{eff}=\frac{1}{2}$态.基态的变化伴随着磁性的急剧变化，从Li $_{2}$ RhO $_{3}$中的6 K自旋玻璃到Ag $_{3}$ LiRh $_{2}$ O $_{6}$中的94 K反铁磁体。这些结果为在两个极限之间调谐材料并创建丰富的磁相图开辟了一条途径。

英文摘要：

Recent observations of novel spin-orbit coupled states have generated tremendous interest in $4d/5d$ transition metal systems. A prime example is the $J_{\text{eff}}=\frac{1}{2}$ state in iridate materials and $α$-RuCl$_{3}$ that drives Kitaev interactions. Here, by tuning the competition between spin-orbit interaction ($λ_{\text{SOC}}$) and trigonal crystal field splitting ($Δ_\text{T}$), we restructure the spin-orbital wave functions into a novel $μ=\frac{1}{2}$ state that drives Ising interactions. This is done via a topochemical reaction that converts Li$_{2}$RhO$_{3}$ to Ag$_{3}$LiRh$_{2}$O$_{6}$, leading to an enhanced trigonal distortion and a diminished spin-orbit coupling in the latter compound. Using perturbation theory, we present an explicit expression for the new $μ=\frac{1}{2}$ state in the limit $Δ_\text{T}\gg λ_{\text{SOC}}$ realized in Ag$_{3}$LiRh$_{2}$O$_{6}$, different from the conventional $J_\text{eff}=\frac{1}{2}$ state in the limit $λ_{\text{SOC}}\gg Δ_\text{T}$ realized in Li$_{2}$RhO$_{3}$. The change of ground state is followed by a dramatic change of magnetism from a 6 K spin-glass in Li$_{2}$RhO$_{3}$ to a 94 K antiferromagnet in Ag$_{3}$LiRh$_{2}$O$_{6}$. These results open a pathway for tuning materials between the two limits and creating a rich magnetic phase diagram.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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