Current-Induced Magnetization Reversal in High Magnetic Fields in Co/Cu/Co Nanopillars

TL;DR

This paper investigates how high current densities can induce magnetization reversal in Co/Cu/Co nanopillars under large perpendicular magnetic fields, revealing a hysteretic resistance change linked to spin-transfer torque effects.

Contribution

It presents experimental evidence of current-induced magnetization reversal in nanopillars at high magnetic fields, supported by a micromagnetic model including spin-transfer torque.

Findings

Abrupt, hysteretic resistance increase at high current densities

Reversal of magnetization to antiparallel alignment with the field

Model suggests complete switching driven by spin-transfer torque

Abstract

Current-induced magnetization dynamics in Co/Cu/Co trilayer nanopillars (~100nm in diameter) has been studied experimentally for large applied fields perpendicular to the layers. An abrupt and hysteretic increase in dynamic resistance is observed at high current densities for one polarity of the current, comparable to the giant magnetoresistance effect observed at low fields. A micromagnetic model, that includes a spin-transfer torque, suggests that the current induces a complete reversal of the thin Co layer to alignment antiparallel to the applied field-that is, to a state of maximum magnetic energy.