Nematic spin correlations in the tetragonal state of uniaxial-strained BaFe2-xNixAs2
Nematic spin correlations in the tetragonal state of uniaxial-strained BaFe2-xNixAs2
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单轴应变 BaFe2-xNixAs2 四方态向列自旋相关性
DOI：
10.1126/science.1251853
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发表时间：
2014-08-08
期刊：
影响因子：
56.9
通讯作者：
Dai, Pengcheng
中科院分区：
文献类型：
--
作者：
Lu, Xingye;Park, J. T.;Dai, Pengcheng
了解高温超导体中电子相的微观起源对于阐明超导机制具有重要意义。在BaFe_（2-x）TxAs_（2-x）（T为Co或Ni）铁磷属化合物的顺磁四元相中，观察到了面内电阻率各向异性。在这里，我们使用非弹性中子散射表明，在这些材料中的低能量自旋激发的变化从四重对称的两倍对称的温度对应的发病的面内电阻率各向异性。由于电阻率和自旋激发各向异性在最佳超导性附近都消失了，我们得出结论，它们可能是密切相关的。
Understanding the microscopic origins of electronic phases in high-transition temperature (high-T-c) superconductors is important for elucidating the mechanism of superconductivity. In the paramagnetic tetragonal phase of BaFe2-xTxAs2 (where T is Co or Ni) iron pnictides, an in-plane resistivity anisotropy has been observed. Here, we use inelastic neutron scattering to show that low-energy spin excitations in these materials change from fourfold symmetric to twofold symmetric at temperatures corresponding to the onset of the in-plane resistivity anisotropy. Because resistivity and spin excitation anisotropies both vanish near optimal superconductivity, we conclude that they are likely intimately connected.