Fermi-liquid regime of the mesoscopic Kondo problem

TL;DR

This paper investigates the low-temperature behavior of the mesoscopic Kondo problem, demonstrating that a Fermi-liquid description accurately captures the quasi-particle spectra through two complementary theoretical approaches.

Contribution

It shows that mean field slave fermion and Nozières' Fermi-liquid approaches yield consistent spectra, confirming the Fermi-liquid regime of the mesoscopic Kondo problem.

Findings

Both approaches produce essentially identical quasi-particle spectra.

The Fermi-liquid description is validated for the low-temperature mesoscopic Kondo regime.

The results support the universality of Fermi-liquid behavior in this context.

Abstract

We consider the low temperature regime of the mesoscopic Kondo problem, and in particular the relevance of a Fermi-liquid description of this regime. Using two complementary approaches -- a mean field slave fermion approximation on the one hand and a Fermi-liquid description "\`a la Nozi\`eres" supplemented by an argument of separation of scale on the other hand -- we show that they both lead to (essentially) the same quasi-particle spectra, providing in this way a strong indication that they both give the correct physics of this regime.