One- and two-channel Kondo model with logarithmic Van Hove singularity: A numerical renormalization group solution

Abstract

Simple scaling consideration and NRG solution of the one-and two-channel Kondo model in the presence of a logarithmic Van Hove singularity at the Fermi level is given. The temperature dependences of local and impurity magnetic susceptibility and impurity entropy are calculated. The low-temperature behavior of the impurity susceptibility and impurity entropy turns out to be non-universal in the Kondo sense and independent of the s − d coupling J. The resonant level model solution in the strong coupling regime confirms the NRG results. In the two-channel case the local susceptibility demonstrates a non-Fermi-liquid power-law behavior.

Kondo effect in twisted bilayer graphene

“…3, upper panel). The main difference from the standard metallic case is an enhanced Kondo temperature [79][80][81] due to the enhanced DoS, which diverges logarithmically at low energies for standard vHs points. Taking the low-energy form of the DoS to be ρ(ω) = ρ 0 (1 + a ln(D/|ω|)), we can integrate Eq.…”

Poor man's scaling: anisotropic Kondo and Coqblin–Schrieffer models

“…For the case of the power law DOS equations (36) and ( In the end, notice that it would be interesting to apply the approach presented in this paper to the case, where the exchange is influenced by Rashba [38] or Dzyaloshinsky-Morya-Kondo interaction [36], to the case when the DOS has a logarithmic singularity [39], to the multi-channel Kondo model [40], and also to the problem of competition between the Kondo effect and RKKY interaction [41]. Another possibly interesting field for application of the presented approach is the models when orbital and spin degrees of freedom of the impurity co-exist [42].…”