Band-dependent superconducting gap in SrFe2(As0.65P0.35)2 studied by angle-resolved photoemission spectroscopy
Band-dependent superconducting gap in SrFe2(As0.65P0.35)2 studied by angle-resolved photoemission spectroscopy
复制标题
利用角分辨光电子能谱研究 SrFe2(As0.65P0.35)2 中能带相关的超导能隙
DOI：
10.1038/s41598-019-52887-y
复制
发表时间：
2019
影响因子：
4.6
通讯作者：
Fujimori A.
中科院分区：
文献类型：
--
作者：
Suzuki H.;Kobayashi T.;Miyasaka S.;Okazaki K.;Yoshida T.;Horio M.;Ambolode L. C. C.;Ota Y.;Yamamoto H.;Shin S.;Hashimoto M.;Lu D. H.;Shen Z.-X.;Tajima S.;Fujimori A.
等价取代铁基化合物SrFe2(As1−xPx)2通过渗透深度、核磁共振和比热测量等实验探针显示出节点超导性的多种证据。直接识别节点超导（SC）间隙结构是具有挑战性的，部分原因是节点的存在不受对称性的保护，而是由顺序参数的偶然符号变化引起的，也因为电子结构的三维性。利用同步加速器和激光角分辨光谱学研究了SrFe2(As0.65P0.35)2在三维动量空间中的SC隙。区中心的三个空穴费米表面（FSs）具有不同大小的SC隙，而区角的电子FSs的SC隙几乎是各向同性的，且与kz无关。作为一种可能的节点SC隙结构，我们提出外孔FS的SC隙沿Z-X [(0,0,2 π)−(π,π, 2π)]方向变化符号。
The isovalent-substituted iron pnictide compound SrFe2(As1−xPx)2exhibits multiple evidence for nodal superconductivity via various experimental probes, such as the penetration depth, nuclear magnetic resonance and specific heat measurements. The direct identification of the nodal superconducting (SC) gap structure is challenging, partly because the presence of nodes is not protected by symmetry but instead caused by an accidental sign change of the order parameter, and also because of the three-dimensionality of the electronic structure. We have studied the SC gaps of SrFe2(As0.65P0.35)2in three-dimensional momentum space by synchrotron and laser-based angle-resolved photoemission spectroscopy. The three hole Fermi surfaces (FSs) at the zone center have SC gaps with different magnitudes, whereas the SC gaps of the electron FSs at the zone corner are almost isotropic andkz-independent. As a possible nodal SC gap structure, we propose that the SC gap of the outer hole FS changes sign around the Z-X [(0, 0, 2π) − (π,π, 2π)] direction.