Band structure and fermi surface of an extremely overdoped iron-based superconductor KFe2As2.
We have performed high-resolution angle-resolved photoemission spectroscopy on heavily overdoped KFe_{2}As_{2} (transition temperature T_{c} = 3 K). We observed several renormalized bands near the Fermi level with a renormalization factor of 2-4. While the Fermi surface around the Brillouin-zone center is qualitatively similar to that of optimally doped Ba_{1-x}K_{x}Fe_{2}As_{2} (x = 0.4; T_{c} = 37 K), the Fermi surface topology around the zone corner (M point) is markedly different: the two electron Fermi surface pockets are completely absent due to an excess of hole doping. This result indicates that the electronic states around the M point play an important role in the high-T_{c} superconductivity of Ba_{1-x}K_{x}Fe_{2}As_{2} and suggests that the interband scattering via the antiferromagnetic wave vector essentially controls the T_{c} value in the overdoped region.
Sato
T
T
Department of Physics, Tohoku University, Sendai 980-8578, Japan and TRiP, Japan Science and Technology Agency (JST), Kawaguchi 332-0012, Japan.
Nakayama
K
K
Sekiba
Y
Y
Richard
P
P
Xu
Y-M
YM
Souma
S
S
Takahashi
T
T
Chen
G F
GF
Luo
J L
JL
Wang
N L
NL
Ding
H
H