Static and Dynamic Magnetism in Underdoped Superconductor BaFe1.92Co0.08As2
Static and Dynamic Magnetism in Underdoped Superconductor BaFe1.92Co0.08As2
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DOI：
10.1103/physrevlett.103.087002
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发表时间：
2009-08-21
影响因子：
8.6
通讯作者：
Mandrus, D.
中科院分区：
文献类型：
--
作者：
Christianson, A. D.;Lumsden, M. D.;Mandrus, D.
我们报告的BaFe 1.92Co 0.08As 2单晶的中子散射测量。通过T-C冷却后，磁布拉格峰强度降低了6%。的自旋动力学表现出8毫电子伏的各向异性三维相互作用的差距。在T-C以下，额外的强度出现在类似于4.5（0.5）meV的能量处，类似于先前在其他铁基超导体中观察到的自旋共振。没有进一步的间隙的自旋激发观察到低于T-C的能量下降到2毫电子伏。这些观测结果表明，从磁布拉格位置到自旋共振的光谱权重的重新分配，表明静态磁序和超导性之间的直接竞争。
We report neutron scattering measurements on single crystals of BaFe1.92Co0.08As2. The magnetic Bragg peak intensity is reduced by 6% upon cooling through T-C. The spin dynamics exhibit a gap of 8 meV with anisotropic three-dimensional interactions. Below T-C additional intensity appears at an energy of similar to 4.5(0.5) meV, similar to previous observations of a spin resonance in other Fe-based superconductors. No further gapping of the spin excitations is observed below T-C for energies down to 2 meV. These observations suggest the redistribution of spectral weight from the magnetic Bragg position to a spin resonance, demonstrating the direct competition between static magnetic order and superconductivity.