论文标题
BA $ _3 $ CUSB $ _2 $ o $ _9 $由氧气稳定
Spin-orbital liquid in Ba$_3$CuSb$_2$O$_9$ stabilized by oxygen holes
论文作者
论文摘要
在Hexagonal ba $ _3 $ _3 $ cusb $ _2 $ _2 $ _9 $中，cu $^{2+} $ o $ $ _6 $ $ _6 $ _6 $ o $ $ _6 $ o $ _6 $ _6 $ _6 $ _2 $ _9 $都没有jahn-teller扭曲的变形。在这里，通过谐振X射线散射和吸收实验，我们表明氧2 $ p $孔在稳定这种自旋轨道液态方面起着至关重要的作用。这些氧气孔出现在“反应” SB $^{5+} $ \ rightarrow $ sb $^{3+} $ $+$+$两个氧气孔中，并且这些孔可以连接到铜离子上。具有氧气2 $ p $孔的六角阶段也展出了一种新颖的电荷 - 轨道动力学，在Ba $ _3 $ _3 $ cusb $ _2 $ _2 $ o $ _9 $的正常阶段不存在，带有Jahn-Teller Tallorttion和Cu 3 $ D $ d $ orbital Order。目前的工作为具有小或负电荷转移能量的过渡金属氧化物中的旋转式轨道纠缠液状态开辟了新的途径。
Both the Jahn-Teller distortion of Cu$^{2+}$O$_6$ octahedra and magnetic ordering are absent in hexagonal Ba$_3$CuSb$_2$O$_9$ suggesting a Cu 3$d$ spin-orbital liquid state. Here, by means of resonant x-ray scattering and absorption experiment, we show that oxygen 2$p$ holes play crucial role in stabilizing this spin-orbital liquid state. These oxygen holes appear due to the "reaction" Sb$^{5+}$$\rightarrow$Sb$^{3+}$ $+$ two oxygen holes, with these holes being able to attach to Cu ions. The hexagonal phase with oxygen 2$p$ holes exhibits also a novel charge-orbital dynamics which is absent in the orthorhombic phase of Ba$_3$CuSb$_2$O$_9$ with Jahn-Teller distortion and Cu 3$d$ orbital order. The present work opens up a new avenue towards spin-charge-orbital entangled liquid state in transition-metal oxides with small or negative charge transfer energy.
