20-024 Doping-induced disorder and conductivity anisotropy in the spin density wave state of iron...
Doping-induced disorder and conductivity anisotropy
in the spin density wave state of iron pnictides
Dheeraj Kumar Singh, Yunkyu Bang
Physical Review B 101, 155101 (2020)
We examine the role of doped impurity atoms on the conductivity anisotropy of the spin-density wave state in iron pnictides. The conductivity is calculated in a self-consistent spin-density wave state with random impurities in a two-orbital model. We find that the increase in impurity concentration leads to an increased suppression of conductivity in both the antiferromagnetic and ferromagnetic directions. However, the conductivity anisotropy is larger in comparison to the Drude-weight anisotropy in the hole-doped regions. The difference between the two is explained in terms of the anisotropic scattering by the impurities. We demonstrate the effect of the anisotropic impurity scattering by calculating the modulation in the density of states introduced by a single impurity. It is also shown that an increase in the Drude-weight anisotropy with changing carrier concentration, which results mainly from the reconstructed band characteristics, may be directly linked to a similar anisotropy in the density-of-states modulation caused by the impurity atom.