2017/11/03 by W. Zhou, Wei Zhou, F. Ke +22
Materials Science · Physics and Astronomy · #Condensed matter physics #Electrical resistivity and conductivity #Electron #Fermi level #Fermi liquid theory #Iron-based superconductors research #Magnetic and transport properties of perovskites and related materials #Physics #Quantum mechanics #Rare-earth and actinide compounds #Spin (aerodynamics) #Superconductivity #Thermodynamics #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.96.184503
published as Phys. Rev. B 96, 184503 (2017)
openalex publication_date 2017/11/03 · openalex created_date 2017/11/10 · arxiv created 2018/08/23 · arxiv updated 2018/08/24 · openalex updated_date 2026/08/05
Non-Fermi-liquid (NFL) phenomena associated with correlation effects have been widely observed in the phase diagrams of unconventional superconducting families. Exploration of the correlation between the normal state NFL, regardless of its microscopic origins, and the superconductivity has been argued as a key to unveiling the mystery of the high-Tc pairing mechanism. Here we systematically investigate the pressure-dependent in-plane resistivity (\ensuremathρ) and Hall coefficient (RH) of a high-quality 112-type Fe-based superconductor Ca_1\ensuremath-xLaxFe_1\ensuremath-yCoyAs2 (x=0.2,y=0.02). With increasing pressure, the normal-state resistivity of the studied sample exhibits a pronounced crossover from non-Fermi-liquid to Fermi-liquid behaviors. Accompanied with this crossover, Tc is gradually suppressed. In parallel, the extremum in the Hall coefficient RH(T) curve, possibly due to anisotropic scattering induced by spin fluctuations, is also gradually suppressed. The symbiosis of NFL and superconductivity implies that these two phenomena are intimately related. Further study on the pressure-dependent upper critical field reveals that the two-band effects are also gradually weakened with increasing pressure and reduced to the one-band Werthamer-Helfand-Hohenberg limit in the low-Tc regime. Overall, our paper supports the picture that NFL, multigap, and extreme RH(T) are all of the same magnetic origin, i.e., the spin fluctuations in the 112 iron arsenide superconductors.