Dresden 2020 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 47: Poster Session Correlated Electrons 2
TT 47.27: Poster
Wednesday, March 18, 2020, 15:00–19:00, P2/3OG
RKKY driven quenching of local moments in Kondo dominated multi impurity models and Kondo insulators — •Fabian Eickhoff and Frithjof Anders — Technische Universität Dortmund, Lehrstuhl für Theoretische Physik II, Dortmund
For a single spin S→ ferromagnetically coupled to a metallic host, the Kondo effect is absent and a spinful groundstate remains. However, if an additional Anderson-type impurity orbital O is added, such that antiferromagnetic RKKY interaction JRKKYSO→S→ is generated, S→ will always be quenched at zero temperature. For TKO ≫ JRKKY, the quenching occurs below the temperature scale T∝ exp(−TKO/JRKKY) where ⟨ SO→S→⟩ ≈ 0 at all temperatures. Using a new type of approximation for the wide band limit, we demonstrate that such a RKKY driven quenching of local moments on a scale T occurs in multi impurity Anderson Hamiltonians as well, requiring at least three impurity sites. We show, that the formation of local moments due to a single Kondo-hole, is a direct consequence of RKKY driven local moment quenching and associated with an exponentially suppressed T. This goes beyond the scope of well established two impurity physics and sheds some new light on emerging magnetic moments and their screening in multi-impurity models as well as in periodic systems.