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arXiv 2301.09446cond-mat.str-el
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具有短程条纹关联的部分无序海森堡反铁磁体

Partially disordered Heisenberg antiferromagnet with short-range stripe correlations

G. G. Blesio, F. T. Lisandrini, M. G. Gonzalez

AI总结:

本文利用矩阵乘积态方法研究S=1/2填充正方晶格海森堡反铁磁体,计算完整相图,并在弱阻挫区域发现部分无序相,其中Néel序保持不变而中心自旋呈现指数衰减双条纹关联。

摘要:

Néel序的零点量子涨落可以在与晶格弱耦合的准孤儿自旋之间产生有效相互作用。在$\sqrt{3}\times\sqrt{3}$畸变三角晶格上,这一现象导致了一种关联的部分无序相。在本文中,我们使用矩阵乘积态方法研究了一个类似的模型:$S=1/2$填充正方晶格。通过调节交换振幅,我们从$J'/J=0$时的正方晶格加中心孤儿自旋,过渡到$J'/J=1$时的联合杰克晶格,再到$J/J'=0$时包含所有自旋的正方晶格。我们计算了完整的反铁磁相图,该相图由亚铁磁序和Néel序主导,并与已有结果进行了比较。最重要的是,我们在弱阻挫区域发现了一个部分无序相。在该相中,来自正方晶格的Néel序不受影响,而中心自旋形成一种具有指数衰减双条纹关联的集体态。我们还通过引入一个有序交错磁场作用于正方子晶格来研究量子涨落的作用,发现当来自Néel序的涨落被抑制时,中心自旋呈铁磁有序。

英文摘要:

Zero-point quantum fluctuations of a Néel order can produce effective interactions between quasi-orphan spins weakly coupled to the lattice. On the $\sqrt{3}\times\sqrt{3}-$distorted triangular lattice, this phenomenon leads to a correlated partially disordered phase. In this article, we use matrix product state methods to study a similar model: the $S=1/2$ stuffed square lattice. Tunning the exchange amplitudes we go from a square lattice plus orphan central spins at $J'/J =0$, to the union jack lattice at $J'/J=1$, and a square lattice including all spins at $J/J'=0$. We calculate the complete antiferromagnetic phase diagram, dominated by ferrimagnetic and Néel orders, and compare with existing results. Most importantly, we find a partially disordered phase in the weakly frustrated regime. In this phase, the Néel order from the square lattice is unaffected, while the central spins form a collective state with exponentially decaying double striped correlations. We also study the role of quantum fluctuations by introducing an ordering staggered magnetic field on the square sublattice, and find that the central spins order ferromagnetically when fluctuations from the Néel order are suppressed.

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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