Ground-state properties of Na2IrO3 determined from an ab initio Hamiltonian and its extensions containing Kitaev and extended Heisenberg interactions
Ground-state properties of Na2IrO3 determined from an ab initio Hamiltonian and its extensions containing Kitaev and extended Heisenberg interactions
复制标题
Na2IrO3 的基态性质由从头算哈密顿量及其包含基塔耶夫和扩展海森堡相互作用的扩展确定
DOI：
10.1103/physrevb.96.054434
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发表时间：
2017
影响因子：
3.7
通讯作者：
Imada Masatoshi
中科院分区：
文献类型：
--
作者：
Okubo Tsuyoshi;Shinjo Kazuya;Yamaji Youhei;Kawashima Naoki;Sota Shigetoshi;Tohyama Takami;Imada Masatoshi
我们研究的基态性质的基础上最近提出的ab initioHamilton Kitaev和扩展海森堡相互作用表示的数值计算。为了克服以往研究中采用的精确对角化方法中系统尺寸小的局限性[Y。Yamaji，Phys. Rev. Lett. 113，107201（2014）PRLTA 00031 -900710.1103/PhysRevLett.113.107201]，我们应用二维密度矩阵重整化群和无限大小张量网络方法。通过计算在更大的系统规模，我们严格测试的准确对角化结果的有效性。结果一致地表明，的基态是一个磁有序态与锯齿形配置与实验观察和以前的对角化研究一致。除了精确对角化的研究，这两个独立的方法的应用进一步揭示了一致的和丰富的相图附近的锯齿相超出了精确对角化的可访问性。例如，在参数空间远离的控制的三角形畸变的从头算值，我们发现三个阶段：（i）有序相的磁矩相互对齐在120度方向上的每三个六边形，（ii）磁有序相与16个网站的晶胞，和（iii）有序相与推测不相称的周期性的时刻。这表明，潜在的丰富的磁性结构可能会出现在化合物中的钠以外。目前的结果也有助于建立的第一性原理方法在再现现有的实验结果，从而进一步有助于找到一条路线，实现Kitaev自旋液体的准确性。
We investigate the ground state properties ofbased on numerical calculations of the recently proposedab initioHamiltonian represented by Kitaev and extended Heisenberg interactions. To overcome the limitation posed by small tractable system sizes in the exact diagonalization study employed in a previous study [Y. Yamaji , Phys. Rev. Lett. 113, 107201 (2014)PRLTAO0031-900710.1103/PhysRevLett.113.107201], we apply a two-dimensional density matrix renormalization group and an infinite-size tensor-network method. By calculating at much larger system sizes, we critically test the validity of the exact diagonalization results. The results consistently indicate that the ground state ofis a magnetically ordered state with zigzag configuration in agreement with experimental observations and the previous diagonalization study. Applications of the two independent methods in addition to the exact diagonalization study further uncover a consistent and rich phase diagram near the zigzag phase beyond the accessibility of the exact diagonalization. For example, in the parameter space away from theab initiovalue ofcontrolled by the trigonal distortion, we find three phases: (i) an ordered phase with the magnetic moment aligned mutually in 120 degrees orientation on every third hexagon, (ii) a magnetically ordered phase with a 16-site unit cell, and (iii) an ordered phase with presumably incommensurate periodicity of the moment. It suggests that potentially rich magnetic structures may appear incompounds forother than Na. The present results also serve to establish the accuracy of the first-principles approach in reproducing the available experimental results thereby further contributing to finding a route to realize the Kitaev spin liquid.