Absence of a Holelike Fermi Surface for the Iron-Based K0.8Fe1.7Se2 Superconductor Revealed by Angle-Resolved Photoemission Spectroscopy
Absence of a Holelike Fermi Surface for the Iron-Based K0.8Fe1.7Se2 Superconductor Revealed by Angle-Resolved Photoemission Spectroscopy
复制标题
角分辨光电发射光谱揭示铁基 K0.8Fe1.7Se2 超导体不存在孔状费米面
DOI：
10.1103/physrevlett.106.187001
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发表时间：
2011-05-03
影响因子：
8.6
通讯作者：
Ding, H.
中科院分区：
文献类型：
--
作者：
Qian, T.;Wang, X. -P.;Ding, H.
我们对新的铁基超导体K0.8Fe1.7Se2（Tc约为30K）进行了角分辨光电子能谱研究。与我们的局部密度近似计算相比，通过2.5倍的因子重整化，观察到清晰的带色散，表明相对较强的相关效应。只有类电子能带穿过费米能，在M（pi，0）处形成近似圆形的费米面（FS）。在伽马的类孔带下沉到费米能量以下90 meV，间接带隙为30 meV，到达类电子带的底部。在这种超导体中观察到的FS拓扑有利于在M点处的类电子FS之间的（pi，pi）FS间散射，与其他铁基超导体形成鲜明对比，这些铁基超导体有利于类孔和类电子FS之间的（pi，0）FS间散射。
We have performed an angle-resolved photoemission spectroscopy study of the new iron-based superconductor K0.8Fe1.7Se2 (T-c similar to 30 K). Clear band dispersion is observed with the overall bandwidth renormalized by a factor of 2.5 compared to our local density approximation calculations, indicating relatively strong correlation effects. Only an electronlike band crosses the Fermi energy, forming a nearly circular Fermi surface (FS) at M (pi, 0). The holelike band at Gamma sinks similar to 90 meV below the Fermi energy, with an indirect band gap of 30 meV, to the bottom of the electronlike band. The observed FS topology in this superconductor favors (pi, pi) inter-FS scattering between the electronlike FSs at the M points, in sharp contrast to other iron-based superconductors which favor (pi, 0) inter-FS scattering between holelike and electronlike FSs.