相关论文: Spin-Transfer Excitations of Permalloy Nanopillars…
We present electrical measurements of high-frequency magnetic dynamics excited by spin-polarized currents in Co/Cu/Ni80Fe20 nanopillar devices, with a magnetic field applied perpendicular to the sample layers. As a function of current and…
Spin transfer torque-induced high-frequency dynamics of single thin cobalt-layer nanopillars of circular and elliptical shape have been observed directly. Two types of precessional modes can be identified as a function of magnetic field…
We describe direct electrical measurements of microwave-frequency dynamics in individual nanomagnets that are driven by spin transfer from a DC spin-polarized current. We map out the dynamical stability diagram as a function of current and…
Using thin film pillars ~100 nm in diameter, containing two ferromagnetic Co layers of different thicknesses separated by a paramagnetic Cu spacer, we examine effects of torques due to spin-polarized currents flowing perpendicular to the…
We consider a quasi one-dimensional configuration consisting of two small pieces of ferromagnetic material separated by a metallic one and contacted by two metallic leads. A spin-polarized current is injected from one lead. Our goal is to…
We investigate the interplay between spin currents and spin waves in nanofabricated Permalloy waveguides with geometrical constrictions. Using propagating spin-wave spectroscopy, micromagnetic simulations, and analytical modeling, we…
We explore the dynamics of spiral spin waves in Permalloy nano-elements with variable aspect ratio of geometric dimensions, and their potential use as improved spin wave emitters with no or little biasing field required. Numerical results…
We perform 3D micromagnetic simulations of current-driven magnetization dynamics in nanoscale exchange biased spin-valves that take account of (i) back action of spin-transfer torque on the pinned layer, (ii) non-linear damping and (iii)…
We study domain wall (DW) dynamics in permalloy nanowires excited by alternating spin-polarized current applied perpendicular to the nanowire. Spin torque ferromagnetic resonance measurements reveal that DW oscillations at a pinning site in…
Spin-torque oscillators are strong candidates as nano-scale microwave generators and detectors. However, because of large amplitude-phase coupling (non-linearity), phase noise is enhanced over other linear auto-oscillators. One way to…
The spin-transfer torque from a DC spin-polarized current can generate highly-coherent magnetic precession in nanoscale magnetic-multilayer devices. By measuring linewidths of spectra from the resulting resistance oscillations, we argue…
We investigated the ferromagnetic resonance signals in a polycrystalline permalloy thin strip under in-plane low static magnetic field. A series of DC voltages, which contain ferromagnetic resonance or spin wave resonance signals, were…
We study the current and temperature dependences of the microwave voltage emission of spin-valve nanopillars subjected to an in-plane magnetic field and a perpendicular-to-plane current. Despite the complex multilayer geometry, clear…
We calculated the main dynamic parameters of the spin polarized current induced magnetic vortex oscillations in nanopillars, such as the range of current density, where a vortex steady oscillations exist, the oscillation frequency and orbit…
A new current induced spin-torque transfer effect has been observed in a single ferromagnetic layer without resorting to multilayers. At a specific current density of one polarity injected from a point contact, abrupt resistance changes due…
We study, both experimentally and by numerical modeling, the magnetic dynamics that can be excited in a magnetic thin-film nanopillar device using the spin torque from a spatially localized current injected via a 10s-of-nm-diameter…
We utilized microwave spectroscopy to study the magnetization oscillations locally induced in a Permalloy film by a pure spin current, which is generated due to the spin Hall effect in an adjacent Pt layer. The oscillation frequency is…
Current-induced magnetic excitations in Co/Cu/Co bilayer nanopillars ($\sim$50 nm in diameter) have been studied experimentally at low temperatures for large applied fields perpendicular to the layers. At sufficiently high current densities…
As predicted by Slonczewski and Berger, the possibility of exciting microwave oscillations in a nanomagnet by a spin-polarized current has been recently demonstrated. This observation opens very important perspectives of applications in RF…
Spin-polarized electrical transport is investigated in $ Al_{2}O_{3}/Ni_{80}Fe_{20}/Al_{2}O_{3}$ thin films for permalloy thickness between 6 and 20nm. The degree of spin-polarization of the current flowing in the plane of the film is…