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arXiv · 1506.04381

Kondo effect in a fermionic hierarchical model

Giuseppe Benfatto·Giovanni Gallavotti·Ian Jauslin
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Abstract

In this paper, a fermionic hierarchical model is defined, inspired by the Kondo model, which describes a 1-dimensional lattice gas of spin-1/2 electrons interacting with a spin-1/2 impurity. This model is proved to be exactly solvable, and is shown to exhibit a Kondo effect, i.e. that, if the interaction between the impurity and the electrons is antiferromagnetic, then the magnetic susceptibility of the impurity is finite in the 0-temperature limit, whereas it diverges if the interaction is ferromagnetic. Such an effect is therefore inherently non-perturbative. This difficulty is overcome by using the exact solvability of the model, which follows both from its fermionic and hierarchical nature.

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Giuseppe Benfatto, Giovanni Gallavotti, Ian Jauslin. 2015-09-18. Kondo effect in a fermionic hierarchical model. https://doi.org/10.1007/s10955-015-1378-7

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