Low Energy Properties of the Kondo chain in the RKKY regime

TL;DR

This paper investigates the low energy behavior of the Kondo chain in the RKKY regime, revealing how anisotropy influences transport properties and localization effects, with extended analysis including electron interactions and spin correlations.

Contribution

It extends previous work by analyzing scattering competition, incorporating short-range interactions, and calculating spin correlations in the Kondo chain model.

Findings

Helical symmetry is spontaneously broken in the easy-plane anisotropy regime.

Localization effects are parametrically suppressed due to anisotropy.

Theoretical predictions suggest experimental setups to observe these phenomena.

Abstract

We study the Kondo chain in the regime of high spin concentration where the low energy physics is dominated by the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction. As has been recently shown (A. M. Tsvelik and O. M. Yevtushenko, Phys. Rev. Lett 115, 216402 (2015)), this model has two phases with drastically different transport properties depending on the anisotropy of the exchange interaction. In particular, the helical symmetry of the fermions is spontaneously broken when the anisotropy is of the easy plane type (EP). This leads to a parametrical suppression of the localization effects. In the present paper we substantially extend the previous theory, in particular, by analyzing a competition of forward- and backward- scattering, including into the theory short range electron interactions and calculating spin correlation functions. We discuss applicability of our theory and possible experiments which could support the theoretical findings.