A Close Correlation between the Logarithmic Quasiparticle Energy and Superconducting Transition Temperatures of Iron-Pnictide Compounds

Abstract

One of difficult problems in iron-based superconductors (normal state) is that the temperature (T) variation of the electrical resistivity deviates from the T2 law. Here we resolve this problem by assuming that the systems are truly 3-dimensional (3D) Fermi liquids. Because of interactions and the presence of Fermi surface, the quasiparticle energy measured from the Fermi surface, e, contains, as a function of momentum p with the Fermi momentum p0, a (p − p0)3 ln|p − p0| term which produces a e2 ln|e| term in the density-of-states function. This term gives rise to a T2 ln T term in the electronic specific heat coefficient, impurity resistivity and total resistivity. Spin-antisymmetric short-wavelength density fluctuations creates a T2 ln T variation of the magnetic susceptibility. We show that existing experimental data obey universally this T2 ln T law. Through this analysis we find a close correlation between the magnitude of the e2 ln|e| term and superconducting transition temperatures; this suggests t...