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arXiv 0707.0892cond-mat.str-el
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Kagome格点Heisenberg反铁磁体的基态

Ground State of the Kagome Lattice Heisenberg Antiferromagnet

Rajiv R. P. Singh, David A. Huse

摘要:

利用二聚体极限附近的级数展开,我们证明了Kagome晶格上海森堡反铁磁体的基态是一个具有36格点晶胞的价键晶体(VBC),每个格点的能量为$E/J=-0.433\pm0.001$ .正如Nikolic和Senthil所讨论的那样,它是一个“完美六边形”的蜂窝晶格。基态与具有最大数目的“完美六边形”的其它有序态(例如条纹有序态)之间的能量差为$0.001 J$级。具有周期性边界条件的36点系统的能量进一步降低了一定量的$0.005\pm 0.001 J$,与精确对角化一致。VBC的每个晶胞都有两个单重态,它们的简并度在展开式中没有提升到$6th$阶。我们估计该能量差小于$0.001 J$。两个领先的订单微扰理论发现最低能量的三重激发是色散和局限于“完美的六边形”。

英文摘要:

Using series expansions around the dimer limit, we show that the ground state of the Heisenberg Antiferromagnet on the Kagome Lattice appears to be a Valence Bond Crystal (VBC) with a 36-site unit cell, and an energy per site of $E/J=-0.433\pm0.001$. It is a honeycomb lattice of `perfect hexagons' as discussed by Nikolic and Senthil. The energy difference between the ground state and other ordered states with the maximum number of `perfect hexagons', such as a stripe-ordered state, is of order $0.001 J$. The energy of the 36-site system with periodic boundary conditions is further lowered by an amount of $0.005\pm 0.001 J$, consistent with Exact Diagonalization. Every unit cell of the VBC has two singlet states whose degeneracy is not lifted to $6th$ order in the expansion. We estimate this energy difference to be smaller than $0.001 J$. Two leading orders of perturbation theory find the lowest-energy triplet excitations to be dispersionless and confined to the `perfect hexagons'.

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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