新型铁基超导体角分辨光电子能谱研究  

Angle-resolved photoemission spectroscopy studies on new iron-based superconductors

作　　者：丁洪[1] 钱天[1] 汪晓平[1] 

机构地区：[1]中国科学院物理研究所,北京100190

出　　处：《物理》2011年第8期523-526,共4页Physics

基　　金：国家重点基础研究发展计划(批准号:2010CB923000);国家自然科学基金(批准号:11004232;11050110422)资助项目

摘　　要：最近发现的新型122结构的铁基超导体掀起了铁基高温超导研究的又一轮热潮.文章利用角分辨光电子能谱实验手段,研究了这类新型铁基材料的电子结构、费米面拓扑和超导能隙.实验结果表明,其在布里渊区中心的能带结构及费米面与其他铁基超导体存在明显差异,并导致嵌套在粒子-空穴通道的费米面消失.另外,在布里渊区边缘的电子型费米面发现了较强的并且有各向同性的超导能隙.这些结果对可能的超导配对机制提出了严格的限制.The recent discovery of new iron chalcogenide superconductors with the 122 crystal structure has generated fresh excitement in the investigation of iron-based high-Tc superconductors. Here we present the results of our measurements of their band structure, Fermi surface （FS） and superconducting gap studied by angle-resolved photoemission spectroscopy. We find that the band structure and FS topology at the center of the Brillouin zone are significantly different from those of other iron-based superconductors, resulting in the disappearance of FS nesting in the particle-hole channel. In addition, we have observed strong and isotropic superconducting gaps on the electron-like FS sheets around the zone corner. All of these results impose severe constraints on possible superconducting pairing mechanisms.

关 键 词：铁基超导体 超导能隙 费米面拓扑 电子结构 超导电子配对 

分 类 号：O511[理学—低温物理]