Fluctuating orders induced non-Fermi-liquid behavior near quantum critical point in iron-based superconductors

The non-Fermi-liquid behavior near quantum critical point (QCP) in iron-based superconductors (IBSCs) is a matter of considerable debate. Recently, we have proposed a novel transport theory quantifying scattering by multi-order fluctuations, yielding a new resistivity model, i.e., ρ=ρ_a+(ρ_b²+α²T²+β²B²)^1/2(see also another contributed talk, She and Li, "A symmetry-breaking analysis for non-Fermi-liquids induced by order fluctuations in correlated electron systems"). For IBSCs near QCP, the theory quantitatively explains the widely observed low-T plateau as a result of scattering by antiferromagnetic (AFM) fluctuations, and the unusual linear T and B scaling at high T and B induced by thermal- and magnetic-vortex fluctuations. Furthermore, the scaling transition from T² to T under increasing T and doping is explained by the increase of vortex fluctuations relative to AFM fluctuations. We present supporting evidence by comparing the predictions with data of dozens of samples. It thus forms a novel framework to clarify the difference between IBSCs and cuprates, successfully quantifying the feature of weaker AFM fluctuations in LiFe_1-xCo_xAs, and stronger vortex fluctuations in BaFe₂(As_1-xP_x)₂ based on the link between macroscopic resistivity and microscopic fluctuating orders.