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arXiv 0912.2600cond-mat.str-el
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用Schwinger-boson方法研究具有Dzyaloshinskiii-Moriya相互作用的kagome:phase diagram和动力学结构因子

A Schwinger-boson approach to the kagome with Dzyaloshinskii-Moriya interactions: phase diagram and dynamical structure factors

L. Messio, O. Cepas, C. Lhuillier

摘要:

本文用Schwinger-boson平均场论得到了具有Dzyaloshinskiii-Moriya相互作用的Kagome反铁磁体的零温相图。我们发现量子相变(一阶或二阶)之间的不同拓扑自旋液体和Neel有序相(无论是$\sqrt{3} \times \sqrt{3}$状态或所谓的Q=0状态)。在小密度区,所得结果与精确对角化结果有一定的一致性,并简要讨论了平均场处理中的一些问题。我们计算的等时结构因子(和它的角平均值,以允许直接与粉末样品上的实验比较),这扩展了早期的经典戈薇量子制度的工作。我们还讨论了拓扑自旋液体和Neel有序相的动力学结构因子。

英文摘要:

We have obtained the zero-temperature phase diagram of the kagome antiferromagnet with Dzyaloshinskii-Moriya interactions in Schwinger-boson mean-field theory. We find quantum phase transitions (first or second order) between different topological spin liquids and Neel ordered phases (either the $\sqrt{3} \times \sqrt{3}$ state or the so-called Q=0 state). In the regime of small Schwinger-boson density, the results bear some resemblances with exact diagonalization results and we briefly discuss some issues of the mean-field treatment. We calculate the equal-time structure factor (and its angular average to allow for a direct comparison with experiments on powder samples), which extends earlier work on the classical kagome to the quantum regime. We also discuss the dynamical structure factors of the topological spin liquid and the Neel ordered phase.

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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