Evidence of a universal relation between electron-mode coupling and Tc in Ba1－xKxFe2As2 superconductor from laser angle-resolved photoemission spectroscopy
Evidence of a universal relation between electron-mode coupling and Tc in Ba1－xKxFe2As2 superconductor from laser angle-resolved photoemission spectroscopy
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激光角分辨光电子能谱证明 Ba1－xKxFe2As2 超导体中电子模式耦合与 Tc 之间的普遍关系
DOI：
10.1103/physrevb.90.195124
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
and S. Shin
中科院分区：
文献类型：
--
作者：
W. Malaeb;T. Shimojima;Y. Ishida;T. Kondo;K. Okazaki;Y. Ota;K. Ohgushi;K. Kihou;C. H. Lee;A. Iyo;H. Eisaki;S. Ishida;M. Nakajima;S. Uchida;H. Fukazawa;T. Saito;Y. Kohori;and S. Shin
我们对（BaK）铁基超导体的宽掺杂范围进行了激光角分辨光发射光谱（ARPES）研究。我们在色散中观察到一个强大的低结合能（BE）扭结结构（kink1），该结构依赖于掺杂，其能量在最佳掺杂水平处达到峰值，并向欠掺杂和过掺杂方向降低。我们将这种扭结归因于电子模式耦合，这与在同一化合物上观察到与自旋激发相关的类似玻色子模式的非弹性中子散射（INS）和扫描隧道显微镜（STM）的结果非常一致。从激光ARPES数据推导出模态能量与SC转变温度之间的关系遵循了从INS和STM推导出的普遍关系。此外，我们可以在更高的BE下解决另一个扭结（kink2），与kink1相比，它的掺杂和温度依赖性更小，因此可能是不同的来源。
We performed a laser angle-resolved photoemission spectroscopy (ARPES) study on a wide doping range of the(BaK) iron-based superconductor. We observed a robust low-binding energy (BE) kink structure (kink1) in the dispersion which is doping dependent whereby its energy peaks at the optimally doped leveland decreases towards the underdoped and overdoped sides. We attribute this kink to electron-mode coupling in good agreement with the inelastic neutron scattering (INS) and scanning tunneling microscopy (STM) results on the same compound where a similar bosonic mode associated with spin excitations was observed. The relation between the mode energyand the SC transition temperaturededuced from our laser ARPES data follow the universal relation deduced from INS and STM. In addition, we could resolve another kink at higher BE (kink2) showing less doping and temperature dependence compared to kink1 and which thus may be of different origin.