Spectral properties of the one-dimensional two-channel Kondo lattice model

TL;DR

This paper investigates the spectral properties of a one-dimensional two-channel Kondo lattice with SU(N) symmetry, revealing a quantum phase transition between RKKY-dominated and Kondo-screened phases at zero temperature.

Contribution

It provides a detailed analysis of the energy spectrum and identifies the existence of soft modes and spectral gaps in the Kondo phase, highlighting the nature of the quantum phase transition.

Findings

Two distinct phases at half filling: RKKY-dominated and Kondo-screened.

Presence of soft modes with spectral gaps smaller than the Kondo temperature.

A quantum phase transition at zero temperature separating the two phases.

Abstract

We have studied the energy spectrum of a one-dimensional Kondo lattice, where the localized magnetic moments have SU(N) symmetry and two channels of conduction electrons are present. At half filling, the system is shown to exist in two phases: one dominated by RKKY-exchange interaction effects, and the other by Kondo screening. A quantum phase transition point separates these two regimes at temperature $T = 0$. The Kondo-dominated phase is shown to possess soft modes, with spectral gaps much smaller than the Kondo temperature.