Dynamics of spin relaxation in nonequilibrium magnetic nanojunctions

Fuente: arXiv
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Main Authors: Smorka, Rudolf, Thoss, Michael, Žonda, Martin
Format: Preprint
Published: 2021
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author Smorka, Rudolf
Thoss, Michael
Žonda, Martin
author_facet Smorka, Rudolf
Thoss, Michael
Žonda, Martin
contents We investigate nonequilibrium phenomena in magnetic nano-junctions using a numerical approach that combines classical spin dynamics with the hierarchical equations of motion technique for quantum dynamics of conduction electrons. Our focus lies on the spin dynamics, where we observe non-monotonic behavior in the spin relaxation rates as a function of the coupling strength between the localized spin and conduction electrons. Notably, we identify a distinct maximum at intermediate coupling strength, which we attribute to a competition that involves the increasing influence of the coupling between the classical spin and electrons, as well as the influence of decreasing local density of states at the Fermi level. Furthermore, we demonstrate that the spin dynamics of a large open system can be accurately simulated by a short chain coupled to semi-infinite metallic leads. In the case of a magnetic junction subjected to an external DC voltage, we observe resonant features in the spin relaxation, reflecting the electronic spectrum of the system. The precession of classical spin gives rise to additional side energies in the electronic spectrum, which in turn leads to a broadened range of enhanced damping in the voltage.
format Preprint
id arxiv_https___arxiv_org_abs_2109_03476
institution arXiv
publishDate 2021
record_format arxiv
spellingShingle Dynamics of spin relaxation in nonequilibrium magnetic nanojunctions
Smorka, Rudolf
Thoss, Michael
Žonda, Martin
Mesoscale and Nanoscale Physics
We investigate nonequilibrium phenomena in magnetic nano-junctions using a numerical approach that combines classical spin dynamics with the hierarchical equations of motion technique for quantum dynamics of conduction electrons. Our focus lies on the spin dynamics, where we observe non-monotonic behavior in the spin relaxation rates as a function of the coupling strength between the localized spin and conduction electrons. Notably, we identify a distinct maximum at intermediate coupling strength, which we attribute to a competition that involves the increasing influence of the coupling between the classical spin and electrons, as well as the influence of decreasing local density of states at the Fermi level. Furthermore, we demonstrate that the spin dynamics of a large open system can be accurately simulated by a short chain coupled to semi-infinite metallic leads. In the case of a magnetic junction subjected to an external DC voltage, we observe resonant features in the spin relaxation, reflecting the electronic spectrum of the system. The precession of classical spin gives rise to additional side energies in the electronic spectrum, which in turn leads to a broadened range of enhanced damping in the voltage.
title Dynamics of spin relaxation in nonequilibrium magnetic nanojunctions
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2109.03476