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arXiv 0811.0526cond-mat.str-el
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二维反铁磁海森堡模型的实空间重整化群方法

Real space renormalization group approach to the 2d antiferromagnetic Heisenberg model

A. Fledderjohann, A. Klümper, K. H. Mütter

摘要:

本文用重整化群方法研究了二维反铁磁海森堡模型在总自旋为$S=0,1,2$的扇形中的低能行为,由相应的量$Δ_S^{(n)}$,$2^n\times 2^n$,$n=1,2,3,...$导出了4个相邻“$n$团簇”的相互作用矩阵$Δ_S^{(n+1)}$的递推公式.总自旋守恒$S$是明确实现,并发挥重要作用。它示出,如何基态能量$E_S^{(n+1)}$,$S=0,1,2$彼此接近,以增加$n$,即系统大小。相互作用矩阵中最相关的耦合是由$(n+1)$ -团簇上基态$|S,m;n+1>$($m=-S,...,S$)之间的跃迁$<S',m';n+1|S_q^*|S,m;n+1>$产生的,该团簇大小为$2^{n+1}\times 2^{n+1}$,由交错自旋算符$S_q^*$介导

英文摘要:

The low energy behaviour of the 2d antiferromagnetic Heisenberg model is studied in the sector with total spins $S=0,1,2$ by means of a renormalization group procedure, which generates a recursion formula for the interaction matrix $Δ_S^{(n+1)}$ of 4 neighbouring "$n$ clusters" of size $2^n\times 2^n$, $n=1,2,3,...$ from the corresponding quantities $Δ_S^{(n)}$. Conservation of total spin $S$ is implemented explicitly and plays an important role. It is shown, how the ground state energies $E_S^{(n+1)}$, $S=0,1,2$ approach each other for increasing $n$, i.e. system size. The most relevant couplings in the interaction matrices are generated by the transitions $<S',m';n+1|S_q^*|S,m;n+1>$ between the ground states $|S,m;n+1>$ ($m=-S,...,S$) on an $(n+1)$-cluster of size $2^{n+1}\times 2^{n+1}$, mediated by the staggered spin operator $S_q^*$

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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