Superconductivity without nesting in LiFeAs.
We have studied the electronic structure of the nonmagnetic LiFeAs (T(c)∼18  K) superconductor using angle-resolved photoemission spectroscopy. We find a notable absence of the Fermi surface nesting, strong renormalization of the conduction bands by a factor of 3, high density of states at the Fermi level caused by a van Hove singularity, and no evidence for either a static or a fluctuating order except superconductivity with in-plane isotropic energy gaps. Our observations suggest that these electronic properties capture the majority of ingredients necessary for the superconductivity in iron pnictides.
Borisenko
S V
SV
Leibniz-Institute for Solid State Research, IFW-Dresden, D-01171 Dresden, Germany.
Zabolotnyy
V B
VB
Evtushinsky
D V
DV
Kim
T K
TK
Morozov
I V
IV
Yaresko
A N
AN
Kordyuk
A A
AA
Behr
G
G
Vasiliev
A
A
Follath
R
R
Büchner
B
B