2018/07/31 by V. A. Shestakov, M. M. Korshunov, O. V. Dolgov
Materials Science · Physics and Astronomy · #Impurity #Ionized impurity scattering #Iron-based superconductors research #Phase transition #Physics of Superconductivity and Magnetism #Rare-earth and actinide compounds #Scattering #Sign (mathematics) #State (computer science) #Superconductivity #Transition temperature #cond-mat.supr-con
paper · pdf · doi:10.3390/sym10080323
published as Symmetry 10, 323 (2018) · 11 pages, 8 figures, published in the Special Issue of Symmetry "Gap Symmetry and Structure of Superconductors", http://www.mdpi.com/journal/symmetry/special_issues/Gap_symmetry_structure_superconductors
openalex created_date 2018/07/10 · openalex publication_date 2018/08/06 · arxiv created 2018/08/14 · arxiv updated 2018/08/16 · openalex updated_date 2026/08/05
We study the dependence of the superconducting gaps on both the disorder and the temperature within the two-band model for iron-based materials. In the clean limit, the system is in the s± state with sign-changing gaps. Scattering by nonmagnetic impurities leads to the change of the sign of the smaller gap, resulting in a transition from the s± to the s++ state with the sign-preserving gaps. We show here that the transition is temperature-dependent. Thus, there is a line of s±→s++ transition in the temperature–disorder phase diagram. There is a narrow range of impurity scattering rates, where the disorder-induced s±→s++ transition occurs at low temperatures, but then the low-temperature s++ state transforms back to the s± state at higher temperatures. With increasing impurity scattering rate, the temperature of such s++→s± transition shifts to the critical temperature Tc, and only the s++ state is left for higher amounts of disorder.