Current-induced magnetization dynamics in Co/Cu/Co trilayer nanopillars (approximately 100 nm in diameter) have been studied experimentally at low temperatures for large applied fields perpendicular to the layers. At 4.2 K an abrupt and hysteretic increase in 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.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1103/PhysRevLett.91.067203 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Inter- and Intrasublattice Spin Mixing Conductance of the Antiferromagnetic Spin Pumping Effect in α-Fe_{2}O_{3}/Pt.
Phys Rev Lett
December 2024
Department of Materials Physics, Nagoya University, Nagoya, Aichi 464-8603, Japan.
The spin pumping effect in antiferromagnets, which ultimately converts THz waves into a spin current, is the key physical mechanism leading to an essential function which harnesses the THz technology and spintronics. Here, we report thorough experimental investigations of the spin current induced by the antiferromagnetic spin pumping effect in epitaxial α-Fe_{2}O_{3} thin films having two distinct dynamic modes and unambiguously show that both the inter- and intrasublattice spin mixing conductance are equally substantial. Our experimental insight is an important advance for understanding the physics of transduction between the spin current and the staggered magnetization dynamics at THz frequency.
View Article and Find Full Text PDFCreating and Deleting a Single Dipolar Skyrmion by Surface Spin Twists.
Nano Lett
January 2025
Anhui Province Key Laboratory of Low-Energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China.
We report deterministic operations on single dipolar skyrmions confined in nanostructured cuboids by using in-plane currents. We achieve highly reversible writing and deleting of skyrmions in a simple cuboid without any artificial defects or pinning sites. The current-induced creation of skyrmions is well-understood through the spin-transfer torque acting on surface spin twists of the spontaneous 3D ferromagnetic state, caused by the magnetic dipole-dipole interaction of the uniaxial FeSn magnet with a low-quality factor.
View Article and Find Full Text PDFAC Magnetometry Using Nano-ferrofluid Cladded Multimode Interferometric Fiber Optic Sensors for Power Grid Monitoring Applications.
ACS Appl Nano Mater
December 2024
Mechanical Engineering & Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States.
The AC magnetic field response of the superparamagnetic nano-ferrofluid is an interplay between the Neel and Brownian relaxation processes and is generally quantified via the susceptibility measurements at high frequencies. The high frequency limit is dictated by these relaxation times which need to be shorter than the time scale of the time varying magnetic field for the nano-ferrofluid to be considered in an equilibrium state at each time instant. Even though the high frequency response of ferrofluid has been extensively investigated for frequencies up to GHz range by non-optical methods, harnessing dynamic response by optical means for AC magnetic field sensing in fiber-optic-based sensors-field remains unexplored.
View Article and Find Full Text PDFElectrical Spin State Manipulation in All-Magnet Heterojunctions Using a Ferromagnetic Spin Source.
Adv Mater
December 2024
Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117583, Singapore.
The ability to electrically manipulate spin states in magnetic materials is essential for the advancement of energy-efficient spintronic device, which is typically achieved in systems composed of a spin source and a magnetic target, where the magnetic state of the target is altered by a charge current. While theories suggest that ferromagnets could function as more versatile spin sources, direct experimental studies involving only the spin source and target layers have been lacking. Here electrical manipulation of spin states in noncolinear antiferromagnet MnSn using ferromagnets (Ni, Fe, NiFe, CoFeB) as the spin sources is reported.
View Article and Find Full Text PDFLarge Spin Hall Efficiency and Current-Induced Magnetization Switching in Ferromagnetic Heusler Alloy CoMnAl-Based Magnetic Trilayers.
Adv Sci (Weinh)
December 2024
Shanghai Key Laboratory of Special Artificial Microstructure Materials and School of Physics Science and Engineering, Tongji University, Shanghai, 200092, China.
Article Synopsis
- * Recent research shows that ferromagnetic materials are effective spin sources, with a focus on developing those that exhibit high spin Hall efficiency.
- * The study reports a high spin Hall efficiency in the ferromagnetic Heusler alloy CoMnAl (CMA), achieving values of 0.077 and 0.029 in different phases, leading to advancements in SOT device technology.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!