Pseudogap Formation above the Superconducting Dome in Iron-Pnictides
Pseudogap Formation above the Superconducting Dome in Iron-Pnictides
复制标题
铁磷族元素中超导圆顶上方赝能隙的形成
DOI：
10.1080/14786435.2014.887861
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
T. Shimojima et al.
中科院分区：
文献类型：
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作者：
Hiroshi Hata;Minori Goto;Akinobu Yamaguchi;Tomonori Sato;Yoshinobu Nakatani;and Yukio Nozaki;T. Shimojima et al.
要解决重费米子化合物Uru-Si中17.5K以下的隐藏有序的本质，识别哪些对称性在隐藏有序跃迁以下被破坏是最重要的步骤之一。最近对电子结构的几个实验表明，隐序相中的费米面与假定反铁磁性的巡回电子图框架内的能带结构计算结果非常接近。这为带的顺序轴折叠提供了强有力的证据，对应于平移对称性的破坏。此外，通过测量电子结构中的面内磁各向异性和有效质量各向异性，以及正交晶格扭曲，有越来越多的证据表明隐藏有序相中的四重旋转对称性破缺。这种被破坏的四重对称性给出了一个严格的约束，即隐序参数的对称性应该属于简并型不可约表示。我们还讨论了时间反转对称性也被打破的可能性，这进一步缩小了表征隐藏有序的序参数。
To resolve the nature of the hidden order below 17.5 K in the heavy-fermion compound URu Si, identifying which symmetries are broken below the hidden-order transition is one of the most important steps. Several recent experiments on the electronic structure have shown that the Fermi surface in the hidden-order phase is quite close to the result of band-structure calculations within the framework of itinerant electron picture assuming the antiferromagnetism. This provides strong evidence for the band folding along the axis with the ordering vector of, corresponding to broken translational symmetry. In addition to this, there is growing evidence for fourfold rotational symmetry breaking in the hidden-order phase from measurements of the in-plane magnetic anisotropy and the effective mass anisotropy in the electronic structure, as well as the orthorhombic lattice distortion. This broken fourfold symmetry gives a stringent constraint that the symmetry of the hidden-order parameter should belong to the degenerate-type irreducible representation. We also discuss a possibility that time reversal symmetry is also broken, which further narrows down the order parameter that characterizes the hidden order.