Exact results on the Kondo-lattice magnetic polaron

TL;DR

This paper provides exact solutions for the magnetic polaron in the Kondo lattice, clarifying the nature of eigenstates and decay dynamics in the thermodynamic limit.

Contribution

It derives complete eigenstates for finite lattices and identifies the correct scattering states in the infinite lattice limit, advancing the theoretical understanding of magnetic polarons.

Findings

Complete eigenstates for finite lattice systems derived.

Identification of scattering states in the infinite lattice limit.

Analysis of down-electron decay dynamics provided.

Abstract

In this work we revise the theory of one electron in a ferromagnetically saturated local moment system interacting via a Kondo-like exchange interaction. The complete eigenstates for the finite lattice are derived. It is then shown, that parts of these states lose their norm in the limit of an infinite lattice. The correct (scattering) eigenstates are calculated in this limit. The time-dependent Schr\"odinger equation is solved for arbitrary initial conditions and the connection to the down-electron Green's function and the scattering states is worked out. A detailed analysis of the down-electron decay dynamics is given.