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Related papers: Frequency Modulation of Spin-Transfer Oscillators

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We study the current controlled modulation of a nano-contact spin torque oscillator. Three principally different cases of frequency non-linearity ($d^{2}f/dI^{2}_{dc}$ being zero, positive, and negative) are investigated. Standard…

Materials Science · Physics 2015-03-13 P. K. Muduli , Ye. Pogoryelov , S. Bonetti , G. Consolo , Fred Mancoff , Johan Åkerman

The impact of radiofrequency (rf) currents on the direct current (dc) driven switching dynamics in current-perpendicular-to-plane nanoscale spin valves is demonstrated. The rf currents dramatically alter the dc driven free layer…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 S. H. Florez , J. A. Katine , M. Carey , L. Folks , O. Ozatay , B. D. Terris

Manipulating spin currents in magnetic insulators is a key technology in spintronics. We theoretically study a simple inversion-asymmetric model of quantum antiferromagnets, where both the exchange interaction and the magnetic field are…

Mesoscale and Nanoscale Physics · Physics 2019-12-13 Tatsuhiko N. Ikeda

We demonstrate that the spin-polarized electron current can interact with a microwave electric field in a resonant manner. The spin-orbit interaction gives rise to an effective magnetic field proportional to the electric current. In the…

Materials Science · Physics 2009-11-10 B. A. Glavin , K. W. Kim

Transfer of angular momentum from a spin-polarized current to a ferromagnet provides an efficient means to control the dynamics of nanomagnets. A peculiar consequence of this spin-torque, the ability to induce persistent oscillations of a…

Other Condensed Matter · Physics 2015-06-25 V. S. Pribiag , I. N. Krivorotov , G. D. Fuchs , P. M. Braganca , O. Ozatay , J. C. Sankey , D. C. Ralph , R. A. Buhrman

New mechanism of magnetoresistance, based on tunneling-emission of spin polarized electrons from ferromagnets (FM) into semiconductors (S) and precession of electron spin in the semiconductor layer under external magnetic field, is…

Materials Science · Physics 2009-11-10 A. M. Bratkovsky , V. V. Osipov

The discovery that a spin polarized current can exert a large torque on a ferromagnet through a transfusion of spin angular momentum, offers a new way to control a magnetization by simple current injection, without the help of an applied…

Vortex-based spin-torque oscillators can be made from extended spin valves connected to an electrical nanocontact. We study the implementation of frequency shift keying modulation in these oscillators. Upon a square modulation of the…

Materials Science · Physics 2015-03-17 M. Manfrini , T. Devolder , Joo-Von Kim , P. Crozat , C. Chappert , W. Van Roy , L. Lagae

We propose a method for inducing magnetization reversal using an AC spin current polarized perpendicular to the equilibrium magnetization of the free magnetic layer. We show that the critical AC spin current is significantly smaller than…

Mesoscale and Nanoscale Physics · Physics 2015-06-05 Tom Dunn , Alex Kamenev

When a spin-polarized current flows through a ferromagnetic (FM) metal, angular momentum is transferred to the background magnetization via spin-transfer torques. In antiferromagnetic (AFM) materials, however, the corresponding problem is…

Mesoscale and Nanoscale Physics · Physics 2015-06-15 Ran Cheng , Qian Niu

This paper shows that the presence of two dynamical regimes, characterized by different precessional-axis, is the origin of the non-monotonic behavior of the output integrated power for large-amplitude magnetization precession driven by…

Other Condensed Matter · Physics 2009-11-13 G. Siracusano , G. Finocchio , A. La Corte , G. Consolo , L. Torres , B. Azzerboni

In the framework of phenomenological model we consider dynamics of a compensated collinear antiferromagnet (AFM) in the presence of spin-polarised current. The model is based on the assumption that AFM spins are localised and spin torque is…

Materials Science · Physics 2010-03-16 H. Gomonay , V. Loktev

Spin-orbit torque arising from the spin-orbit-coupled surface states of topological insulators enables current-induced control of magnetization with high efficiency. Here, alternating-current (AC) driven magnetization reversal is…

We fabricated superconducting coplanar waveguide resonator with leads for dc bias, which enables the ac conductivity measurement under dc bias. The current and the magnetic field dependences of resonance properties were measured, and…

Superconductivity · Physics 2019-02-20 H. Kurokawa , F. Nabeshima , A. Maeda

We have directly measured coherent high-frequency magnetization dynamics in ferromagnet films induced by a spin-polarized DC current. The precession frequency can be tuned over a range of several gigahertz, by varying the applied current.…

Condensed Matter · Physics 2009-11-10 W. H. Rippard , M. R. Pufall , S. Kaka , S. E. Russek , T. J. Silva

In this work we formulate a generalized theoretical model to describe the nonlinear dynamics observed in combined frequency-amplitude modulators whose characteristic parameters exhibit a nonlinear dependence on the input modulating signal.…

Mathematical Physics · Physics 2015-05-13 G. Consolo , V. Puliafito , G. Finocchio , L. Lopez-Diaz , R. Zivieri , L. Giovannini , F. Nizzoli , G. Valenti , B. Azzerboni

The responses of the electrical current and the current-induced spin transfer torque (CISTT) to an ac bias in addition to a dc bias in a magnetic tunnel junction are investigated by means of the time-dependent nonquilibrium Green function…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Zhen-Gang Zhu , Gang Su , Qing-Rong Zheng , Biao Jin

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…

Other Condensed Matter · Physics 2009-11-11 J. C. Sankey , I. N. Krivorotov , S. I. Kiselev , P. M. Braganca , N. C. Emley , R. A. Buhrman , D. C. Ralph

DC current induced magnetization reversal and magnetization oscillation was observed in 500 nm large size Co90Fe10/Cu/Ni80Fe20 pillars. A perpendicular external field enhanced the coercive field separation between the reference layer…

Mesoscale and Nanoscale Physics · Physics 2017-04-05 Linqiang Luo , Mehdi Kabir , Nam Dao , Salinporn Kittiwatanakul , Michael Cyberey , Stuart A. Wolf , Mircea Stan , Jiwei Lu

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…

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