English
Related papers

Related papers: Spin Torque Dynamics with Noise in Magnetic Nano-S…

200 papers

Spin polarized current may transfer angular momentum to a ferromagnet, resulting in a spin-torque phenomenon. At the same time the shot noise, associated with the current, leads to a non-equilibrium stochastic force acting on the…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 A. L. Chudnovskiy , J. Swiebodzinski , A. Kamenev

We explore how non-equilibrium noise affects spin-torque switching elements and oscillators. To do so we first discuss the deterministic dynamics of magnetic tunnel junctions, introducing a convenient set of slow and fast degrees of…

Mesoscale and Nanoscale Physics · Physics 2011-10-18 T. Dunn , A. L. Chudnovskiy , A. Kamenev

We theoretically investigate nonequilibrium spin fluctuations in a ferromagnet induced by a light pulse. Using a Lindblad equation consistent with the Landau-Lifshitz-Gilbert equation, we compute the autocorrelation function of…

Mesoscale and Nanoscale Physics · Physics 2025-04-03 Tetsuya Sato , Shinichi Watanabe , Mamoru Matsuo , Takeo Kato

We consider a biaxial macrospin with an easy and hard axis, and study its dynamical evolution under the combined effects of thermal noise and spin transfer torque. The spin-torque is associated with both a perpendicularly magnetized…

Mesoscale and Nanoscale Physics · Physics 2015-06-19 Daniele Pinna , Daniel L. Stein , Andrew D. Kent

We apply a recently developed quantum theory of spin transfer torque to study the effect of the quantum noise in spin transfer process on the magnetization switching in spin-torque-driven devices. The quantum noise induces considerable…

Mesoscale and Nanoscale Physics · Physics 2013-07-10 Yong Wang , Yan Zhou , Fu-Chun Zhang

In the presence of spatial variation of the magnetization direction, electric current noise causes a fluctuating spin-transfer torque that increases the fluctuations of the ferromagnetic order parameter. By the fluctuation-dissipation…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Jorn Foros , Arne Brataas , Yaroslav Tserkovnyak , Gerrit E. W. Bauer

Spin noise spectroscopy is emerging as a powerful technique for studying the dynamics of various spin systems also beyond their thermal equilibrium and linear response. Here, we study spin fluctuations of room-temperature neutral atoms in a…

Atomic Physics · Physics 2021-07-21 V. Guarrera , R. Gartman , G. Bevilacqua , W. Chalupczak

The dynamics and thermal equilibrium of spin waves (magnons) in a quantum ferromagnet as well as the macroscopic magnetisation are investigated. Thermal noise due to an interaction with lattice phonons and the effects of spatial…

Quantum Physics · Physics 2018-11-06 Jan Jeske , Ángel Rivas , Muhammad H. Ahmed , Miguel A. Martin-Delgado , Jared H. Cole

Recent experimental results have pushed the limits of magnetization dynamics to pico- and femtosecond timescales. This ultra-fast spin dynamics occurs in extreme conditions of strong and rapidly varying fields and high temperatures. This…

Materials Science · Physics 2009-11-13 U. Atxitia , O. Chubykalo-Fesenko , R. W. Chantrell , U. Nowak , A Rebei

We report the theoretical investigation of noise spectrum of spin current and spin transfer torque for non-colinear spin polarized transport in a spin-valve device which consists of normal scattering region connected by two ferromagnetic…

Mesoscale and Nanoscale Physics · Physics 2015-06-12 Yunjin Yu , Hongxin Zhan , Langhui Wan , Bin Wang , Yadong Wei , Qingfeng Sun , Jian Wang

We discuss the effects of thermal noise on the magnetic response of a lateral ferromagnetic Josephson junction with spin-orbit coupling and out-of-plane magnetization. The direction of the magnetic moment in the ferromagnetic layer can be…

Superconductivity · Physics 2020-10-29 C Guarcello , FS Bergeret

We introduce a highly sensitive and relatively simple technique to observe magnetization motion in single Ni nanoparticles, based on charge sensing by electron tunneling at millikelvin temperature. Sequential electron tunneling via the…

Mesoscale and Nanoscale Physics · Physics 2018-01-17 W. C. Jiang , G. Nunn , P. Gartland , D. Davidović

We calculate the real time non-equilibrium dynamics of quantum spin systems at finite temperatures. The mathematical framework originates from the $C^*$-approach to quantum statistical mechanics and is applied to samples investigated by…

Mesoscale and Nanoscale Physics · Physics 2015-06-16 Kolja Them , T. Stapelfeldt , E. Y. Vedmedenko , R. Wiesendanger

Not all noise in experimental measurements is unwelcome. Certain fundamental noise sources contain valuable information about the system itself -- a notable example being the inherent voltage fluctuations that exist across any resistor…

Disordered Systems and Neural Networks · Physics 2009-11-10 S. A. Crooker , D. G. Rickel , A. V. Balatsky , D. L. Smith

Recent measurements in current-driven spin valves demonstrate magnetization fluctuations that deviate from semiclassical predictions. We posit that the origin of this deviation is spin shot noise. On this basis, our theory predicts that…

Mesoscale and Nanoscale Physics · Physics 2019-02-25 Alireza Qaiumzadeh , Arne Brataas

We investigate nonequilibrium phenomena in magnetic nano-junctions using a numerical approach that combines classical spin dynamics with the hierarchical equations of motion technique for quantum dynamics of conduction electrons. Our focus…

Mesoscale and Nanoscale Physics · Physics 2024-02-26 Rudolf Smorka , Michael Thoss , Martin Žonda

A microscopic theory of spin fluctuations of localized electrons interacting with optically cooled nuclear spin bath has been developed. Since nuclear spin temperature may stay low enough for macroscopically long time, the nuclear spin…

Mesoscale and Nanoscale Physics · Physics 2015-05-05 D. S. Smirnov

Spin noise spectroscopy is a technique to measure magnetization fluctuations, a subject of increasing relevance in ultrafast spintronics. We investigate numerically the equilibrium spin noise of ferro- and antiferromagnets within an…

Materials Science · Physics 2024-11-28 Julius Schlegel , Martin Evers , Ulrich Nowak

We theoretically and numerically investigate the spin fluctuations induced in a thermal atomic ensemble by an external fluctuating uniaxial magnetic field, in the context of a standard spin noise spectroscopy (SNS) experiment. We show that…

Quantum Physics · Physics 2023-10-05 J. Delpy , S. Liu , P. Neveu , C. Roussy , Th. Jolicoeur , F. Bretenaker , F. Goldfarb

One of the cornerstones of spintronics is the application of a spin-transfer torque to a nanomagnet, driving the magnetization of the nanomagnet into a steady-state precession and realizing a spin-torque oscillator. Such a steady state,…

Mesoscale and Nanoscale Physics · Physics 2025-01-22 Pieter M. Gunnink , Tim Ludwig , Alexander Shnirman , Rembert A. Duine
‹ Prev 1 2 3 10 Next ›