Related papers: Current-driven microwave oscillations in current p…
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…
We have studied microwave emission from a current-perpendicular-to-plane pseudo spin valve nanopillars with Heusler alloy Co2Fe(Ga0.5Ge0.5) electrodes. Large emission amplitude exceeding 150 nV/Hz^0.5, partly owing to the large…
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…
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…
Nanopillar spin valve devices are typically comprised of two ferromagnetic layers: a reference layer and a free layer whose magnetic orientation can be changed by both an external magnetic field and through the introduction of…
The generation of oscillations in the microwave frequency range is one of the most important applications expected from spintronics devices exploiting the spin transfer phenomenon. We report transport and microwave power measurements on…
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 measure the microwave signals produced by spin-torque-driven magnetization dynamics in patterned magnetic multilayer devices at room temperature, as a function of the angle of a magnetic field applied in the sample plane. We find strong…
We investigate the dynamics of two coupled vortices driven by spin transfer. We are able to independently control with current and perpendicular field, and to detect, the respective chiralities and polarities of the two vortices. For…
Using measurements of the spectra of microwave-frequency resistance oscillations, we determine the phase diagram of magnetic excitations caused by torques from DC spin-polarized currents in (thin permalloy)/copper/(thick permalloy)…
We present an experimental and theoretical study of the low-field dynamics of current-driven vortex oscillations in nanocontacts based on spin-valve multilayers. These oscillations appear as low-frequency (250-500 MHz) excitations in the…
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…
An anomalous (inverse) spin accumulation in the nonmagnetic spacer may build up when the spin valve consists of magnetic films having different spin symmetries. This leads to wavy-like dependence of spin-transfer torque on the angle between…
The spin-transfer nano-oscillator (STNO) offers the possibility of using the transfer of spin angular momentum via spin-polarized currents to generate microwave signals. However, at present STNO microwave emission mainly relies on both…
Two-level fluctuations of the magnetization state of pseudo spin-valve pillars Co(10 nm)/Cu(10 nm)/Co(30 nm) embedded in electrodeposited nanowires (~40 nm in diameter, 6000 nm in length) are triggered by spin-polarized currents of 10^7…
We report on propagating spin-wave spectroscopy measurements carried out on coplanar nano-antenna devices made from a Si/SiO$_2$/Ru(5nm)/Co(20)/Pt(5nm) film. The measurements were analyzed in detail by employing newly developed theoretical…
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 investigate the origin of the experimentally observed varying current-frequency nonlinearity of the propagating spin wave mode in nano-contact spin torque oscillators. Nominally identical devices with 100 nm diameter are characterized by…
The charge and spin diffusion equations taking into account spin-flip and spin-transfer torque were numerically solved using a finite element method in complex non-collinear geometry with strongly inhomogeneous current flow. As an…
We present an experimental and theoretical study of the magnetic field dependence of the mode frequency of thermally excited spin waves in rectangular shaped nanopillars of lateral sizes 60x100, 75x150, and 105x190 nm2, patterned from…