Density matrix renormalization group numerical study of the kagome antiferromagnet
Density matrix renormalization group numerical study of the kagome antiferromagnet
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DOI：
10.1103/physrevlett.101.117203
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发表时间：
2008-09-12
影响因子：
8.6
通讯作者：
Sheng, D. N.
中科院分区：
文献类型：
--
作者：
Jiang, H. C.;Weng, Z. Y.;Sheng, D. N.
利用密度矩阵重整化群方法对kagome晶格上的自旋1/2反铁磁海森堡模型进行了数值研究。我们发现基态是一种磁性无序自旋液体，其特征是自旋-自旋相关函数在实空间呈指数衰减，磁结构因子在相应的磁波矢量上显示系统大小无关的峰值。根据大尺寸实验结果外推得到自旋三重态激发隙E(S=1)=0.055 +/- 0.005，证实了无间隙单重态激发的存在。讨论了这种奇异自旋液体的物理性质。
We numerically study the spin 1/2 antiferromagnetic Heisenberg model on the kagome lattice using the density-matrix renormalization group method. We find that the ground state is a magnetically disordered spin liquid, characterized by an exponential decay of spin-spin correlation function in real space and a magnetic structure factor showing system-size independent peaks at commensurate magnetic wave vectors. We obtain a spin triplet excitation gap Delta E(S=1)=0.055 +/- 0.005 by extrapolation based on the large size results, and confirm the presence of gapless singlet excitations. The physical nature of such an exotic spin liquid is also discussed.