论文标题
几乎理想的$ j _ {\ rm eff} $ $ = $ 1/2虹膜卤化物的结构，电子和磁性
Structural, electronic, and magnetic properties of nearly-ideal $J_{\rm eff}$ $=$ 1/2 iridium halides
论文作者
论文摘要
重型过渡金属磁铁，带有$ J _ {\ rm eff} $ $ = $ 1/2电子接地状态，由于他们喜欢举办新的量子自旋液体和超导体的新类别，因此引起了最近的兴趣。不幸的是，由于大多数候选材料中非立我们的本地畸变的重要性，因此具有理想$ j _ {\ rm eff} $ $ $ $ $ $ 1/2状态的模型系统很少。在这项工作中，我们确定了卤化卤化物系统的家族[即k $ _2 $ ircl $ _6 $，k $ _2 $ irbr $ _6 $，（nh $ _4 $）$ _ 2 $ _ 2 $ _ 2 $ ircl $ _6 $，na $ _2 $ _2 $ _2 $ _6 \ cdotp $ 6（h $ _2 $ o）具有IR $ $ $^$^$ j $ j $ j {4+} $ j $ j $ j {4+;尽管低温全局晶体结构有所不同，但EFF} $ $ = $ 1/2限制。我们还找到了三个无水系统的有序磁接地状态，k $ _2 $ irbr $ _6 $揭示了I型抗铁磁性的单晶中子衍射。这种自旋构型与对面部中心磁铁中明显的Kitaev交换的期望一致。
Heavy transition metal magnets with $J_{\rm eff}$ $=$ 1/2 electronic ground states have attracted recent interest due to their penchant for hosting new classes of quantum spin liquids and superconductors. Unfortunately, model systems with ideal $J_{\rm eff}$ $=$ 1/2 states are scarce due to the importance of non-cubic local distortions in most candidate materials. In this work, we identify a family of iridium halide systems [i.e. K$_2$IrCl$_6$, K$_2$IrBr$_6$, (NH$_4$)$_2$IrCl$_6$, and Na$_2$IrCl$_6 \cdotp $ 6(H$_2$O)] with Ir$^{4+}$ electronic ground states in extremely close proximity to the ideal $J_{\rm eff}$ $=$ 1/2 limit, despite a variation in the low-temperature global crystal structures. We also find ordered magnetic ground states for the three anhydrous systems, with single crystal neutron diffraction on K$_2$IrBr$_6$ revealing Type-I antiferromagnetism. This spin configuration is consistent with expectations for significant Kitaev exchange in a face-centered-cubic magnet.
