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Related papers: Spin torque oscillator for microwave assisted magn…

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We simulate the spin torque-induced reversal of the magnetization in thin disks with perpendicular anisotropy at zero temperature. Disks typically smaller than 20 nm in diameter exhibit coherent reversal. A domain wall is involved in larger…

Mesoscale and Nanoscale Physics · Physics 2018-12-03 Paul Bouquin , Siddharth Rao , Gouri Sankar Kar , Thibaut Devolder

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…

The microwave assisted magnetisation reversal is modelled in a permalloy micron-sized magnetic ellipsoid. Our simulations confirm that this process requires less field than magnetisation reversal under a static field. This is due to a…

We experimentally study spin-Hall nano-oscillators based on [Co/Ni] multilayers with perpendicular magnetic anisotropy. We show that these devices are capable of single-frequency auto-oscillations at current densities comparable to those in…

Mesoscale and Nanoscale Physics · Physics 2017-07-19 B. Divinskiy , V. E. Demidov , A. Kozhanov , A. B. Rinkevich , S. O. Demokritov , S. Urazhdin

Inplane magnetization reversal of a permalloy/platinum bilayer was detected using the spin rectification effect. Using a sub GHz microwave frequency to excite spin torque ferromagnetic resonance (ST FMR) in the bilayer induces two discrete…

Materials Science · Physics 2020-12-30 Motomi Aoki , Ei Shigematsu , Ryo Ohshima , Syuta Honda , Teruya Shinjo , Masashi Shiraishi , Yuichiro Ando

The magnetization reversal in a single molecular magnet (SMM) weakly coupled to an electrode with spin-dependent splitting of chemical potentials (spin bias) is theoretically investigated by means of the rate equation. A microscopic…

Mesoscale and Nanoscale Physics · Physics 2009-05-14 Hai-Zhou Lu , Bin Zhou , Shun-Qing Shen

We analytically determine the optimal microwave field that allows for the magnetization reversal of a nanomagnet modeled as a macrospin. This is done by minimizing the total injected energy. The results are in good agreement with the fields…

Mesoscale and Nanoscale Physics · Physics 2013-09-02 N. Barros , M. Rassam , H. Kachkachi

The magnetization reversal and dynamics of a spin valve pillar, whose lateral size is 64$\times$64 nm$^2$, are studied by using micromagnetic simulation in the presence of spin transfer torque. Spin torques display both characteristics of…

Materials Science · Physics 2009-11-10 Z. Li , S. Zhang

The effect of undesirable high-frequency free-layer switching in magnetic multilayer systems, referred to as back hopping, is investigated by means of the spin-diffusion model. A possible origin of the back-hopping effect is found to be the…

We numerically study ultra fast resonant spin torque (ST) magnetization reversal in magnetic tunnelling junctions (MTJ) driven by current pulses having a direct current (DC) and a resonant alternating current (AC) component. The…

Materials Science · Physics 2015-05-19 L. Fricke , S. Serrano-Guisan , H. W. Schumacher

We consider a microscopic theory for the spin Hall magnetoresistance (SMR). We generally formulate a spin conductance at an interface between a normal metal and a magnetic insulator in terms of spin susceptibilities. We reveal that SMR is…

Mesoscale and Nanoscale Physics · Physics 2020-11-17 Takeo Kato , Yuichi Ohnuma , Mamoru Matsuo

Magnetic auto-oscillations are damping-compensated magnetization precessions. They can be generated in spin Hall nano-oscillators (SHNO) among others. Current research on these devices is dedicated to create next generation energy-efficient…

Mesoscale and Nanoscale Physics · Physics 2024-06-25 Toni Hache , Anshu Anshu , Tetyana Shalomayeva , Rainer Stöhr , Klaus Kern , Jörg Wrachtrup , Aparajita Singha

Reliable operation of perpendicular spin-transfer-torque magnetic random-access memory (p-STT-MRAM) requires control of magnetic alignment within the synthetic antiferromagnet (SAF) reference layer. At nanopillar dimensions, however,…

Mesoscale and Nanoscale Physics · Physics 2026-05-12 Afan Terko , George Lertzman-Lepofsky , Dieter Suess , Claas Abert , Erol Girt

We have developed a self-aligned, high-yield process to fabricate CPP (current perpendicular to the plane) magnetic sensors of sub 100 nm dimensions. A pinned synthetic antiferromagnet (SAF) is used as the reference layer which minimizes…

Materials Science · Physics 2009-11-10 D. Lacour , J. A. Katine , N. Smith , M. J. Carey , J. R. Childress

Based on the Landau-Lifshitz-Gilbert equation, it can be shown that a circularly-polarized microwave can reverse the magnetization of a Stoner particle through synchronization. In comparison with magnetization reversal induced by a static…

Materials Science · Physics 2009-12-14 Z. Z. Sun , X. R. Wang

A possibility to excite a stable self-oscillation in a perpendicularly magnetized ferromagnet by the spin Hall effect is investigated theoretically. It had been shown that such self-oscillation cannot be stabilized solely by the direct spin…

Mesoscale and Nanoscale Physics · Physics 2017-07-18 Tomohiro Taniguchi

The transfer of spin angular momentum to a nanomagnet from a spin polarized current provides an efficient means of controlling the magnetization direction in nanomagnets. A unique consequence of this spin torque is that the spontaneous…

Mesoscale and Nanoscale Physics · Physics 2018-07-31 Dinesh Kumar , K. Konishi , Nikhil Kumar , S. Miwa , A. Fukushima , K. Yakushiji , S. Yuasa , H. Kubota , C. V. Tomy , A. Prabhakar , Y. Suzuki , A. Tulapurkar

Magnetic random-access memory (MRAM) driven by spin-transfer torque (STT) is a major contender for future memory applications. The energy dissipation involved in writing remains problematic, even with the advent of more efficient…

Using a magnetic resonance force microscope (MRFM), the power emitted by a spin transfer nano-oscillator consisting of a normally magnetized Py$|$Cu$|$Py circular nanopillar is measured both in the autonomous and forced regimes. From the…

Materials Science · Physics 2013-02-20 A. Hamadeh , Grégoire De Loubens , V. V. Naletov , J. Grollier , Ch. Ulysse , V. Cros , O. Klein

The nature of spin wave modes excited by spin-polarized direct current in a spin-torque auto-oscillator based on a magnetic nanocontact was studied by a micromagnetic simulation in the case when the external bias magnetic field was rotated…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 G. Consolo , B. Azzerboni , L. Lopez-Diaz , G. Gerhart , E. Bankowski , V. Tiberkevich , A. N. Slavin