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arXiv 2101.00754cond-mat.str-el
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CuAl2O4中Jeff=1/2态到S=1/2态的压力诱导跃迁

Pressure-induced transition from Jeff=1/2 to S=1/2 states in CuAl2O4

Hwanbeom Cho, Choong H. Kim, Yongmoon Lee, Kazuki Komatsu, Byeong-Gwan Cho, Deok-Yong Cho, Taehun Kim, Chaebin Kim, Younghak Kim, Tae Yeong Koo, Yukio Noda, Hir… 展开作者

Hwanbeom Cho, Choong H. Kim, Yongmoon Lee, Kazuki Komatsu, Byeong-Gwan Cho, Deok-Yong Cho, Taehun Kim, Chaebin Kim, Younghak Kim, Tae Yeong Koo, Yukio Noda, Hiroyuki Kagi, Daniel I. Khomskii, Donghoon Seoung, Je-Geun Park

摘要:

自旋-轨道纠缠态是研究新量子现象的一片沃土。与传统的4d和5d过渡金属化合物的弱相关Jeff=1/2态相反,CuAl 2 O 4的基态具有强库仑U相关的Jeff=1/2态。在这里,我们报告说,令人惊讶的Cu 2+离子的CuAl 2 O 4克服了否则通常强Jahn-Teller失真,而是稳定的SOE状态,虽然铜酸盐具有相对较小的自旋轨道耦合。从X射线吸收光谱和高压X射线衍射研究中,我们得到了明确的证据,杰夫=1/2状态的立方晶格在环境压力下。我们还发现,压力诱导的结构转变为压缩的四角晶格组成的自旋只有S=1/2状态的压力高于Pc=8 GPa。这种从Mott绝缘的Jeff=1/2态到S=1/2态的相变是一种独特的现象,以前没有报道过。我们的研究提供了一个罕见的例子,在强电子关联下的SOE杰夫态和压力诱导跃迁到S=1/2状态。

英文摘要:

The spin-orbit entangled (SOE) Jeff-state has been a fertile ground to study novel quantum phenomena. Contrary to the conventional weakly correlated Jeff=1/2 state of 4d and 5d transition metal compounds, the ground state of CuAl2O4 hosts a Jeff=1/2 state with a strong correlation of Coulomb U. Here, we report that surprisingly Cu2+ ions of CuAl2O4 overcome the otherwise usually strong Jahn-Teller distortion and instead stabilize the SOE state, although the cuprate has relatively small spin-orbit coupling. From the x-ray absorption spectroscopy and high-pressure x-ray diffraction studies, we obtained definite evidence of the Jeff=1/2 state with a cubic lattice at ambient pressure. We also found the pressure-induced structural transition to a compressed tetragonal lattice consisting of the spin-only S=1/2 state for pressure higher than Pc=8 GPa. This phase transition from the Mott insulating Jeff=1/2 to the S=1/2 states is a unique phenomenon and has not been reported before. Our study offers a rare example of the SOE Jeff-state under strong electron correlation and its pressure-induced transition to the S=1/2 state.

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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