The(Ca,R)FeAs_(2)(R=La,Pr,etc.)superconductors with a signature of superconductivity transition above 40 K possess a new kind of block layers that consist of zig-zag As chains.We report the electronic structure of the...The(Ca,R)FeAs_(2)(R=La,Pr,etc.)superconductors with a signature of superconductivity transition above 40 K possess a new kind of block layers that consist of zig-zag As chains.We report the electronic structure of the new(Ca,La)FeAs_(2)superconductor investigated by both band structure calculations and high resolution angle-resolved photoemission spectroscopy measurements.Band structure calculations indicate that there are four hole-like bands around the zone centerΓ(0,0)and two electron-like bands near the zone corner M(π,π)in CaFeAs_(2).In our angle-resolved photoemission measurements on(Ca0.9La0.1)FeAs_(2),we have observed three hole-like bands around theΓpoint and one electron-like Fermi surface near the M(π,π)point.These results provide important information to compare and contrast with the electronic structure of other iron-based compounds in understanding the superconductivity mechanism in the iron-based superconductors.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 10734120the National Basic Research Program of China under Grant Nos 2011CB921703 and 2011CB605903.
文摘The(Ca,R)FeAs_(2)(R=La,Pr,etc.)superconductors with a signature of superconductivity transition above 40 K possess a new kind of block layers that consist of zig-zag As chains.We report the electronic structure of the new(Ca,La)FeAs_(2)superconductor investigated by both band structure calculations and high resolution angle-resolved photoemission spectroscopy measurements.Band structure calculations indicate that there are four hole-like bands around the zone centerΓ(0,0)and two electron-like bands near the zone corner M(π,π)in CaFeAs_(2).In our angle-resolved photoemission measurements on(Ca0.9La0.1)FeAs_(2),we have observed three hole-like bands around theΓpoint and one electron-like Fermi surface near the M(π,π)point.These results provide important information to compare and contrast with the electronic structure of other iron-based compounds in understanding the superconductivity mechanism in the iron-based superconductors.
