Universality between current- and field-driven domain wall dynamics in ferromagnetic nanowires

Spin-polarized electric current exerts torque on local magnetic spins, resulting in magnetic domain-wall (DW) motion in ferromagnetic nanowires. Such current-driven DW motion opens great opportunities toward next-generation magnetic devices controlled by current instead of magnetic field. However, t...

Full description

Saved in:
Bibliographic Details
Published in:arXiv.org 2010-06
Main Authors: Lee, Jae-Chul, Kab-Jin, Kim, Ryu, Jisu, Kyoung-Woong Moon, Sang-Jun, Yun, Gi-Hong Gim, Kang-Soo, Lee, Kyung-Ho, Shin, Hyun-Woo, Lee, Sug-Bong Choe
Format: Article
Language:English
Subjects:
Cobalt
Collapse
Current density
Current efficiency
Domain walls
Ferromagnetism
Low currents
Magnetic anisotropy
Magnetic devices
Magnetic domains
Magnetic fields
Nanotechnology devices
Nanowires
Ohmic dissipation
Platinum
Resistance heating
Spin dynamics
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Spin-polarized electric current exerts torque on local magnetic spins, resulting in magnetic domain-wall (DW) motion in ferromagnetic nanowires. Such current-driven DW motion opens great opportunities toward next-generation magnetic devices controlled by current instead of magnetic field. However, the nature of the current-driven DW motion--considered qualitatively different from magnetic-field-driven DW motion--remains yet unclear mainly due to the painfully high operation current densities J_OP, which introduce uncontrollable experimental artefacts with serious Joule heating. It is also crucial to reduce J_OP for practical device operation. By use of metallic Pt/Co/Pt nanowires with perpendicular magnetic anisotropy, here we demonstrate DW motion at current densities down to the range of 10^9 A/m^2--two orders smaller than existing reports. Surprisingly the current-driven motion exhibits a scaling behaviour identical to the field-driven motion and thus, belongs to the same universality class despite their qualitative differences. Moreover all DW motions driven by either current or field (or by both) collapse onto a single curve, signalling the unification of the two driving mechanisms. The unified law manifests non-vanishing current efficiency at low current densities down to the practical level, applicable to emerging magnetic nanodevices.
ISSN:2331-8422