Coulomb interaction effects and electron spin relaxation in the 1d Kondo lattice model

TL;DR

This paper investigates how Coulomb interactions influence magnetic phases and electron spin relaxation in the one-dimensional Kondo lattice model, revealing conditions that optimize relaxation times and the role of exchange processes.

Contribution

It provides a detailed analysis of Coulomb interaction effects on phase behavior and spin relaxation, highlighting the dominance of exchange processes in decoherence.

Findings

Onsite Coulomb interaction supports ferromagnetic order.

Nearest neighbor Coulomb interaction can induce paramagnetic or ferromagnetic phases.

Optimal parameters exist where electron spin relaxation time is maximized.

Abstract

We study the effects of the Coulomb interaction in the one dimensional Kondo lattice model on the phase diagram, the static magnetic susceptibility and electron spin relaxation. We show that onsite Coulomb interaction supports ferromagnetic order and nearest neighbor Coulomb interaction drives, depending on the electron filling, either a paramagnetic or ferromagnetic order. Furthermore we calculate electron quasiparticle life times, which can be related to electron spin relaxation and decoherence times, and explain their dependence on the strength of interactions and the electron filling in order to find the sweet spot of parameters where the relaxation time is maximized. We find that effective exchange processes between the electrons dominate the spin relaxation and decoherence rate.