Magnetic instability induced by tunnel current in single Co nanoparticles

TL;DR

This paper investigates how tunnel current affects the magnetic stability of single cobalt nanoparticles, showing that electron transport can induce magnetic switching and instability, with potential implications for nanoscale magnetic devices.

Contribution

It demonstrates that tunnel current can induce magnetic instability and switching in single Co nanoparticles, revealing a new mechanism for controlling nanoscale magnetism.

Findings

Tunnel current reduces the magnetic switching field.

Voltage pulses can switch nanoparticle magnetization.

Large currents cause additional magnetization transitions.

Abstract

Measurements of magnetic hysteresis loops in single Co nanoparticles at dilution refrigerator temperatures are presented. The nanoparticles are in electric contact with bulk Al leads via tunnel junctions. The tunnel current versus magnetic field displays a magnetic hysteresis loop. The magnetic switching field is reduced by current, and the magnetization of the nanoparticle can be switched by applying a voltage pulse, demonstrating that the magnetic stability of the nanoparticle is diminished by electron transport. Additional transitions and random switches of magnetization can be driven by large currents.