Doping dependence of Hall coefficient and evolution of coherent electronic state in the normal state of the Fe-based superconductor Ba1−xKxFe

Kenya Ohgushi

¹

,

Yoshihiro Kiuchi

²

Abstract

We investigated the in-plane transport properties of the Fe-based superconductor Ba 1−x K x Fe 2 As 2 with a wide composition range 0 x 0.55. We show that the doping dependence of the Hall coefficient is well described by the Boltzmann equation for a two-band system with a rigid-band approximation. We successfully deduced transport parameters, which suggested that holes with heavier mass conduct more smoothly than electrons. Moreover, the temperature variation of the Hall coefficient indicated that an anomalous coherent state characterized by heavy quasiparticles in hole bands evolved below ∼100 K, predominantly in the optimal and overdoped regions. We argue that this phenomenon can be understood in relation to the pseudopeak structure observed in angle-resolved photoemission spectroscopy.

Normal-state charge dynamics in doped BaFe2As2: Roles of doping and necessary ingredients for superconductivity

“…A difference is that a doped P atom is a weaker scattering center as evidenced by a smaller residual-resistivity component. The doping evolution of ρ ( T ) in K-Ba122 is in sharp contrast to the Co- and P-doping cases1920. Chemically, K doping corresponds to hole doping, but both the magnitude and T dependence of the resistivity only weakly change with doping.…”

Absence of superconductivity in the hole-doped Fe pnictide Ba(Fe1−xMnx)2<

“…1, the resistivity of Mn-Ba122 5 shows a jump at the magneto-structural phase transition temperature and gradually increases below it. This behavior is contrasted with the metallic behaviors of the parent compound and the hole-doped Ba 1−x K x Fe 2 As 2 (K-Ba122) 7 , where the resistivity drops below the transition temperature. A neutron scattering experiment on Mn-Ba122 8 has revealed competition between the stripe-type spin-density-wave (SDW) order [Q Q Q stripe =( 1 2 , 1 2 , 1)] seen in the parent compound and a G-type antiferromagnetic order [Q Q Q G-type =(1, 0, 1)] predominant in the tetragonal phase; in the orthorhombic phase, there are additional inelastic spin excitation peaks which represent the Gtype antiferromagnetic fluctuations.…”

Orbital-anisotropic electronic structure in the nonmagnetic state of BaFe2(As1−xP x )2 superconductors

“…Single crystals of AsP122 with x  = 0.00 ( T N,s  = 136 K), x  = 0.07 ( T N,s  = 114 K), x  = 0.24 ( T N,s  = 55 K, T c  = 16 K), x  = 0.30 ( T c  = 30 K), x  = 0.45 ( T c  = 22 K), x  = 0.52 ( T c  = 15 K), x  = 0.61 ( T c  = 9 K), x  = 0.74, and x  = 0.87 were grown by a self-flux method as described in refs 31 and 32 . Resistivity measurements 32 suggest the high quality of the crystals with a residual resistivity ratio of ≤30.…”