Strongly correlated multi-impurity models: The crossover from a single-impurity problem to lattice models

Kondo holes in strongly correlated impurity arrays: RKKY driven Kondo screening and hole-hole interactions

“…Due to the left/right structure in 1d the number of screening channels can never be larger than two in this case, K 1d ≤ 2, which provides an alternative interpretation of our result in Ref. [32], where we demonstrated that the maximum number of possible screening channels for any MIAM in arbitrary spatial dimensions is limited to the number of Fermi surface states.…”

“…This surprising finding can be very easily explained by studying a slightly modified version of the model, schematically depicted in Fig. 3(b), as we have done in a previous publication [32]. If the coupling to the impurity site at the origin dominates over all others: V 0 ≫ V l , l = 0, the f B,l -orbitals at the sites l = 0 "feel" an effective medium (gray background in Fig.…”

“…3(b)), which includes the influence of the f B,0 -orbital on the conduction band electrons. If the f B,0 -orbital is assumed to be non-interacting, U 0 = 0, the effective c-density of states at the B-sublattice of site l is approximately given by [32]…”

“…for the real part of the free conduction band electron propagator has entered [32]. The comparison of the local conduction electron DOS without impurity ρ 0 1d (ω) and the local DOS at site l with the impurity present is shown in Fig.…”

“…Further we (ii) demonstrate that the emergence of decoupled localized states in a Kondo insulator due to Kondo hole substitution can be understood from a local perspective and does not rely on the periodicity and translational invariance of the lattice model. Using a combination of the NRG and a wide band approximation [32] we (iii) study the effect of Kondo holes in finite impurity clusters as function of the local hole orbital energy and the band center of the conduction electrons and show that breaking PH symmetry can lead to Kondo screening of the hole induced magnetic bound states on low energy scales.…”