Spin gap in Tl2Ru2O7 and the possible formation of Haldane chains in three-dimensional crystals
Spin gap in Tl2Ru2O7 and the possible formation of Haldane chains in three-dimensional crystals
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DOI：
10.1038/nmat1605
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发表时间：
2006-06
期刊：
影响因子：
41.2
通讯作者：
Seongsu Lee;J-G. Park;J-G. Park;D. Adroja;D. Khomskii;S. Streltsov;K. McEwen;H. Sakai;K. Yoshimura;V. Anisimov;Daisuke Mori;R. Kanno;R. Ibberson
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文献类型：
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作者：
Seongsu Lee;J-G. Park;J-G. Park;D. Adroja;D. Khomskii;S. Streltsov;K. McEwen;H. Sakai;K. Yoshimura;V. Anisimov;Daisuke Mori;R. Kanno;R. Ibberson
视在性是物理现象最重要的参数之一。只有两件事决定了相变的普适性：给定系统的维数和序参量的对称性。在大多数情况下，物质的维度是由其晶体结构预先确定的。其中有效维数减少的例子是相当罕见的。在这里，我们表明，三维立方系统的Tl2Ru2O7最有可能演变成一个一维的自旋为1的Haldrons系统的自旋间隙低于120 K，伴随着异常的结构，电阻率和磁化率。我们认为，这些异常是由于Ru 4d电子的轨道排序，与三个自由度之间的强耦合：轨道，自旋和晶格。我们的工作提供了一个独特的例子，自发形成的Halflion系统的洞察不同自由度的有趣的相互作用。
Dimensionality is one of the most important parameters of physical phenomena. Only two things determine the universality class of a phase transition: the dimensionality of a given system and the symmetry of the order parameter. In most cases, the dimensionality of a substance is predetermined by its crystal structure. Examples in which the effective dimensionality is reduced are quite rare. Here we show that the three-dimensional cubic system of Tl2Ru2O7most probably evolves into a one-dimensional spin-one Haldane system with a spin gap below 120 K, accompanied by anomalies in the structure, resistivity and susceptibility. We argue that these anomalies are due to an orbital ordering of Ru 4delectrons, with a strong coupling among three degrees of freedom: orbital, spin and lattice. Our work provides a unique example of the spontaneous formation of Haldane system with an insight into the intriguing interplay of different degrees of freedom.