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arXiv 0810.2312cond-mat.str-el
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二维准晶的反铁磁性

Antiferromagnetism in two-dimensional quasicrystals

Anuradha Jagannathan, Attila Szallas

摘要:

准周期结构具有长程位置有序性,但不受平移不变性的约束。对于通过海森堡耦合相互作用的自旋,人们可以期望在这样的结构中找到新的磁位形。我们已经研究了简单的二维模型的磁性,作为第一步,对理解实验研究的磁性准晶,如Zn-Mg-R(稀土)化合物。我们分析了反铁磁基态和磁振子激发模式的性质,如八角形和彭罗斯平铺二分。在没有挫折的情况下,一个有一个不均匀的尼尔有序基态,与本地交错磁序参量的本地量子涨落。在线性自旋波近似下,我们研究了这种反铁磁体的自旋波谱和波函数。讨论了这些系统中自旋-自旋关联的一些结果。

英文摘要:

Quasiperiodic structures possess long range positional order, but are freed of constraints imposed by translational invariance. For spins interacting via Heisenberg couplings, one may expect therefore to find novel magnetic configurations in such structures. We have studied magnetic properties for simple two dimensional models, as a first step towards understanding experimentally studied magnetic quasicrystals such as the Zn-Mg-R(rare earth) compounds. We analyse properties of the antiferromagnetic ground state and magnon excitation modes for bipartite tilings such as the octagonal and Penrose tilings. In the absence of frustration, one has an inhomogeneous Neel-ordered ground state, with local quantum fluctuations of the local staggered magnetic order parameter. We study the spin wave spectrum and wavefunctions of such antiferromagnets within the linear spin wave approximation. Some results for spin-spin correlations in these systems are discussed.

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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