Indexed by: Journal paper

First Author: Tian Qian

Co-author: Hong Ding,X-L Chen,J-G Guo,Zhong Fang,Xi Dai,Gang Xu,P Richard,Peng Zhang,W-C Jin,X-P Wang

Journal: Physical Review Letters

Included Journals: SCI

Discipline: 物理学

Document Type: J

Volume: 106

Issue: 18

Page Number: 187001

ISSN No.: 0031-9007

Date of Publication: 2011-05-03

Impact Factor: 7.37

Abstract: We have performed an angle-resolved photoemission spectroscopy study of the new iron-based superconductor K 0.8 Fe 1.7 Se 2 (T c∼ 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 (π, 0). The holelike band at Γ sinks∼ 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 (π, π) inter-FS scattering between the electronlike FSs at the M points, in sharp contrast to other iron-based superconductors which favor (π, 0) inter-FS scattering between holelike and electronlike FSs.

Links to published journals: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.106.187001