Kinetics of local $"$magnetic$"$ moment and non-stationary spin-polarized current in the single impurity Anderson-model

TL;DR

This paper provides a theoretical analysis of the dynamics of magnetic moments and spin-polarized currents in a single impurity Anderson model, highlighting conditions for long-lived magnetic states and non-stationary spin currents.

Contribution

It introduces a detailed kinetic framework for localized electron states considering high-order correlations, revealing non-stationary magnetic phenomena in the Anderson model.

Findings

Stationary state is paramagnetic with equal spin occupation.

Long-lived magnetic moments can occur under strong Coulomb interactions.

Non-stationary spin-polarized currents flow in opposite directions temporarily.

Abstract

We perform theoretical investigation of the localized state dynamics in the presence of interaction with the reservoir and Coulomb correlations. We analyze kinetic equations for electron occupation numbers with different spins taking into account high order correlation functions for the localized electrons. We reveal that in the stationary state electron occupation numbers with the opposite spins always have the same value - the stationary state is a $"$paramagnetic$"$ one. $"$Magnetic$"$ properties can appear only in the non-stationary characteristics of the single-impurity Anderson model and in the dynamics of the localized electrons second order correlation functions. We found, that for deep energy levels and strong Coulomb correlations, relaxation time for initial $"$magnetic$"$ state can be several orders larger than for $"$paramagnetic$"$ one. So, long-living $"$magnetic$"$ moment can exist in the system. We also found non-stationary spin polarized currents flowing in opposite directions for the different spins in the particular time interval.