Nonanalytic spin susceptibility of a Fermi liquid: the case of Fe-based pnictides.
We propose an explanation of the peculiar linear temperature dependence of the uniform spin susceptibility chi(T) in ferropnictides. We argue that the linear in T term appears to be due to the nonanalytic temperature dependence of chi(T) in a two-dimensional Fermi liquid. We show that the prefactor of the T term is expressed via the square of the spin-density-wave (SDW) amplitude connecting nested hole and electron pockets. Because of an incipient SDW instability, this amplitude is large, which, along with a small value of the Fermi energy, makes the T dependence of chi(T) strong. We demonstrate that this mechanism is in quantitative agreement with the experiment.
Korshunov
M M
MM
Max-Planck-Institut für Physik komplexer Systeme, D-01187 Dresden, Germany. maxim@mpipks-dresden.mpg.de
Eremin
I
I
Efremov
D V
DV
Maslov
D L
DL
Chubukov
A V
AV