Anomalous Superconducting-Gap Structure of Slightly Overdoped Ba(Fe1-xCox)(2)As-2

作者：Hajiri Tetsuya^*; Ito Takahiro; Matsunami Masaharu; Min Byeong Hun; Kwon Yong Seung; Kimura Shin ichi

来源：Journal of the Physical Society of Japan, 2014, 83(9): 093703.

DOI：10.7566/JPSJ.83.093703

We observed the anisotropic superconducting-gap (SC-gap) structure of a slightly overdoped superconductor, Ba(Fe1-xCox)(2)As-2 (x = 0.1), using three-dimensional (3D) angle-resolved photoemission spectroscopy. Two hole Fermi surfaces (FSs) observed at the Brillouin zone center and an inner electron FS at the zone corner showed a nearly isotropic SC gap in 3D momentum space. However, the outer electron FS showed an anisotropic SC gap with nodes or gap minima around the M and A points. The different anisotropies obtained the SC gap between the outer and inner electron FSs cannot be expected from all theoretical predictions with spin fluctuation, orbital fluctuation, and both competition. Our results provide a new insight into the SC mechanisms of iron pnictide superconductors.

• 出版日期2014-9