2014/01/31 by Camille Aron, Gabriel Kotliar · 3 citations
Materials Science · Mathematics · Physics and Astronomy · #Group (periodic table) #Iron-based superconductors research #Mathematical physics #Mathematics #Perspective (graphical) #Physics #Quantum mechanics #Rare-earth and actinide compounds #Renormalization group #Surface and Thin Film Phenomena #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.91.041110
published as Phys. Rev. B 91, 041110(R) (2015) · 5 p, 3 figs., suppl. mat., published version
arxiv created 2015/01/12 · openalex publication_date 2015/01/12 · arxiv updated 2015/01/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study the emergence of quasiparticles in Hund's metals with an SU(M)\ifmmode×\else\texttimes\fiSU(N)-symmetric Kondo impurity model carrying both spin and orbital degrees of freedom. We show that the coupling of the impurity spin to the conduction electrons can be ferromagnetic, notably for hole-doped iron pnictides. We derive the weak-coupling renormalization group (RG) equations for arbitrary representations of SU(M)\ifmmode×\else\texttimes\fiSU(N). A ferromagnetic spin coupling results in a protracted RG flow, accounting for the surprising particle-hole asymmetry that is observed in the iron-pnictide systems. We establish the low coherence scale TK, which depends on the filling through the impurity representation. We also discuss the temperature dependence of the spin and orbital susceptibilities. Finally, we argue that this mechanism explains the strong valence dependence of the coherence scale observed in dilute transition-metal magnetic alloys.