Orbital character and electron correlation effects on two- and three-dimensional Fermi surfaces in KFe2As2 revealed by angle-resolved photoemission spectroscopy

Frontiers in Physics

Mo, Sung-Kwan¹  Hussain, Zahid¹  Harima, Hisatomo²  Yoshida, Teppei³  Iyo, Akira⁴  Lee, C. H⁴  Kihou, Kunihiro⁴  Eisaki, Hiroshi⁴  Yi, Ming⁵  Moore, Rob⁵  Shen, Zhi-Xun⁵  Lu, Donghui⁵  Ideta, Shin-ichiro⁶  Fujimori, Atsushi⁶  Nishi, Ichiro⁶ 

[1] Advanced Light Source, Lawrence Berkeley National Lab, Berkeley, United States;Kobe University, Kobe, Japan;Kyoto University, Kyoto, Japan;National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan;Stanford Univerisity, Stanford, United States;University of Tokyo, Tokyo, Japan

关键词: iron pnictide superconductor;    angle-resolved photoemission spectroscopy;    Fermi surface;    band structure;    electron correlation;   

DOI  :  10.3389/fphy.2014.00017

学科分类：物理（综合）

来源: Frontiers

【 摘 要 】

We have investigated orbital character and electron correlation effects on Fermi surfaces in the hole-overdoped iron pnictide superconductor KFe2As2, which shows a low Tc of ~4 K, by angle-resolved photoemission spectroscopy. From the polarization-dependence of the ARPES spectra, we have determined the orbital character of each Fermi surface. Electron mass renormalization of each band is quantitatively consistent with de Haas-van Alphen results. The outer beta and middle zeta Fermi surfaces show large renormalization factor of m*/mb ~6-7, while the inner Fermi surface has a smaller factor m*/mb ~2. Middle hole Fermi surface zeta has strong three-dimensionality compared to other Fermi surfaces, indicating the d3z2-r2 orbital character, which may be related to the "octet-line nodes" recently observed by laser ARPES. The observed orbital-dependent mass renormalization would give constraints on the pairing mechanism with line nodes of this system.

【 授权许可】

CC BY