三轴中子散射谱仪的建造及凝聚态物质中磁相互作用的中子散射研究中期报告

The Middle Term Report of The Construction of a Neutron Triple-axis Spectrometer andStudy on the Magnetic Interaction in the Condensed Matter Materials

该研究是973计划“高通量中子散射在凝聚态物质磁相互作用方面的前沿研究”的研究- “三轴中子散射谱仪的建造及凝聚态物质中磁相互作用的中子散射研究中期报告”（2012CB 821401）的中期报告.主要进展包括3个部分.首先,我们基本搭建完成了“翠竹”热中子三轴谱仪.其次,我们在铁基自旋动力学方面取得了-些重要进展,包括B a Fe2 -x N ix A s ,中的量子临界性质和低能自旋激发谱的演化,铁基超导体自旋序来源的总结以及L i缺陷对L iF e A s性质的影响.最后,在理论方面,我们提出了一种独特的铁基超导理论,对二维阻挫系统中的金属-绝缘体相变也进行了讨论.

This report is the middle term report of the sub-topic 1, The Construction of A Neutron Triple-A xis Spectrometer And Studyon The Magnetic Interaction in The Condensed Matter Materials, 2012CB821401 of the 973 program, Advanced Research on The MagneticInteractions in The Condensed Matter Materials by H igh-flux Neutron Scattering. The major results can be summarized into three parts.First, we have almost finished the construction of the Bamboo thermal neutron trip le-ax is spectrometer. Secondly, we have obtainedsome important results in studying the spin dynamics of the Fe-based superconductors, such as the quantum critical properties and theevolution of the low-energy spin excitations in BaFe2-xNixAs2, the review on the origin of the antiferromagnetic orders in the Fe-basedsuperconductors, and the effect of Li deficiencies on the physical properties of LiFeAs. Thirdly, we have proposed a unique theory onthe mechanism of the Fe-based superconductors and discussed the metal-insulator transition in the 2D frustrated system.