Magnetic orders proximal to the Kitaev limit in frustrated triangular systems: Application to Ba 3 IrTi 2 O 9
Magnetic orders proximal to the Kitaev limit in frustrated triangular systems: Application to Ba 3 IrTi 2 O 9
复制标题
受挫三角系统中接近基塔耶夫极限的磁阶：在 Ba 3 IrTi 2 O 9 中的应用
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
H. Kee
中科院分区：
文献类型：
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作者：
A. Catuneanu;J. Rau;Heung;H. Kee
Frustrated transition-metal compounds in which spin-orbit coupling (SOC) and electron correlation work together have attracted much attention recently. In the case of $5d$ transition metals, where SOC is large, ${j}_{ ext{eff}}=1/2$ bands near the Fermi level are thought to encompass the essential physics of the material, potentially leading to a concrete realization of exotic magnetic phases such as the Kitaev spin liquid. Here, we derive a spin model on a triangular lattice based on ${j}_{ ext{eff}}=1/2$ pseudospins that interact via antiferromagnetic Heisenberg ($J$) and Kitaev ($K$) exchanges, and crucially, an anisotropic $(mathrm{ensuremath{Gamma}})$ exchange. Our classical analysis of the spin model reveals that, in addition to small regions of ${120}^{ensuremath{circ}}, {mathbb{Z}}_{2}$/dual-${mathbb{Z}}_{2}$ vortex crystal and nematic phases, the stripy and ferromagnetic phases dominate the $Jensuremath{-}Kensuremath{-}mathrm{ensuremath{Gamma}}$ phase diagram. We apply our model to the $5d$ transition-metal compound, ${mathrm{Ba}}_{3}{mathrm{IrTi}}_{2}{mathrm{O}}_{9}$, in which the ${mathrm{Ir}}^{4+}$ ions form layered two-dimensional triangular lattices. We compute the band structure and nearest-neighbor hopping parameters using ab initio calculations. By combining our ab initio and classical analyses, we predict that ${mathrm{Ba}}_{3}{mathrm{IrTi}}_{2}{mathrm{O}}_{9}$ has a stripy ordered magnetic ground state.
Frustrated transition-metal compounds in which spin-orbit coupling (SOC) and electron correlation work together have attracted much attention recently. In the case of $5d$ transition metals, where SOC is large, ${j}_{ ext{eff}}=1/2$ bands near the Fermi level are thought to encompass the essential physics of the material, potentially leading to a concrete realization of exotic magnetic phases such as the Kitaev spin liquid. Here, we derive a spin model on a triangular lattice based on ${j}_{ ext{eff}}=1/2$ pseudospins that interact via antiferromagnetic Heisenberg ($J$) and Kitaev ($K$) exchanges, and crucially, an anisotropic $(mathrm{ensuremath{Gamma}})$ exchange. Our classical analysis of the spin model reveals that, in addition to small regions of ${120}^{ensuremath{circ}}, {mathbb{Z}}_{2}$/dual-${mathbb{Z}}_{2}$ vortex crystal and nematic phases, the stripy and ferromagnetic phases dominate the $Jensuremath{-}Kensuremath{-}mathrm{ensuremath{Gamma}}$ phase diagram. We apply our model to the $5d$ transition-metal compound, ${mathrm{Ba}}_{3}{mathrm{IrTi}}_{2}{mathrm{O}}_{9}$, in which the ${mathrm{Ir}}^{4+}$ ions form layered two-dimensional triangular lattices. We compute the band structure and nearest-neighbor hopping parameters using ab initio calculations. By combining our ab initio and classical analyses, we predict that ${mathrm{Ba}}_{3}{mathrm{IrTi}}_{2}{mathrm{O}}_{9}$ has a stripy ordered magnetic ground state.