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arXiv 1303.4675cond-mat.str-el
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相对论莫特绝缘体Li $_2$ RhO $_3$的电子结构

Electronic structure of relativistic Mott insulator Li$_2$RhO$_3$

Chao Cao, Yongkang Luo, Zhuan Xu, Jianhui Dai

摘要:

受Na $_2$ IrO $_3$及其4d类似物Li $_2$ RhO $_3$共存电子关联和自旋轨道耦合效应研究的启发,我们对氧化铑化合物进行了第一性原理计算.实验观察到的Li $_2$ RhO $_3$的基态只有同时考虑自旋轨道耦合和在位库仑相互作用才能恢复。在适当的$U$范围内的4d轨道($2\leqslant U\leqslant 4$ eV),锂$_2$ RhO $_3$的基态可以是双原子原子力显微镜或条纹原子力显微镜,两者产生的能隙接近实验观察。此外,竞争磁相之间的总能量差为$2\leqslant U\leqslant 4$ eV内的$\leqslant 3$ meV/Rh,表明化合物中的强磁阻挫。最后,Li $_2$ RhO $_3$的相能不能用只考虑最近邻相互作用的二维Heisenberg-Kitaev模型拟合,我们认为层间相互作用可能是造成这种差异的原因.

英文摘要:

Motivated by studies of coexisting electron correlation and spin-orbit coupling effect in Na$_2$IrO$_3$ and a recent experiment of its 4d analogue Li$_2$RhO$_3$, we performed first-principles calculations of the rhodium oxide compound. The experimentally observed ground state of Li$_2$RhO$_3$ can be recovered only if both spin-orbit coupling and on-site Coulomb interaction are taken into consideration. Within the proper $U$ range for 4d-orbitals ($2\leqslant U\leqslant 4$ eV), the ground state of Li$_2$RhO$_3$ could be either zigzag-AFM or stripy-AFM, both yielding energy gap close to experimental observation. Furthermore, the total energy differences between the competing magnetic phases are $\leqslant 3$ meV/Rh within $2\leqslant U\leqslant 4$ eV, manifesting strong magnetic frustration in the compound. Finally, the phase energy of Li$_2$RhO$_3$ cannot be fitted with the two-dimensional Heisenberg-Kitaev model involving only the nearest neighbor interactions, and we propose that inter-layer interactions may be responsible for the discrepancy.

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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