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Related papers: Quantum Brownian Motion for Magnets

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Thermal fluctuations of nanomagnets driven by spin-polarized currents are treated via the Landau-Lifshitz-Gilbert equation as generalized to include both the random thermal noise field and Slonczewski spin-transfer torque terms. The…

Statistical Mechanics · Physics 2017-09-26 Y. P. Kalmykov , D. Byrne , W. T. Coffey , W. J. Dowling , S. V. Titov , J. E. Wegrowe

We consider the Landau-Lifshitz equation for the spin torque oscillator - a uniaxial ferromagnet in an external magnetic field with polarised spin current driven through it. In the absence of the Gilbert damping, the equation turns out to…

Pattern Formation and Solitons · Physics 2020-04-22 I. V. Barashenkov , Alexander Chernyavsky

We present the stochastic Schroedinger equation for the dynamics of a quantum particle coupled to a high temperature environment and apply it the dynamics of a driven, damped, nonlinear quantum oscillator. Apart from an initial slip on the…

Quantum Physics · Physics 2009-10-31 Walter T. Strunz , Lajos Diosi , Nicolas Gisin , Ting Yu

We obtain the equations of motion for a ferromagnetic Bose condensate of arbitrary spin in the long wavelength limit. We find that the magnetization of the condensate is described by a non-trivial modification of the Landau-Lifshitz…

Other Condensed Matter · Physics 2009-11-13 Austen Lamacraft

We revisit the model of a quantum Brownian oscillator linearly coupled to an environment of quantum oscillators at finite temperature. By introducing a compact and particularly well-suited formulation, we give a rather quick and direct…

Quantum Physics · Physics 2011-05-17 C. H. Fleming , Albert Roura , B. L. Hu

The Landau--Lifshitz--Gilbert equations for the evolution of the magnetization, in presence of an external torque, can be cast in the form of the Lorenz equations and, thus, can describe chaotic fluctuations. To study quantum effects, we…

Quantum Physics · Physics 2015-04-24 Julien Tranchida , Pascal Thibaudeau , Stam Nicolis

We investigate quantum dynamics of the excited electronic states in the double-exchange model at half-filling by solving coupled equations for the quantum evolution of electrons and Landau-Lifshits-Gilbert equation for classical spins. The…

Strongly Correlated Electrons · Physics 2009-05-05 W. Koshibae , N. Furukawa , N. Nagaosa

A theory of Brownian motion is presented for an assembly of vortices. The attempt is motivated by a realization of Dyson' Coulomb gas in the context of quantum condensates. By starting with the time-dependent Landau-Ginzburg (LG) theory,…

Statistical Mechanics · Physics 2022-09-07 Hiroshi Kuratsuji

We show that we can harness two recent experimental developments to build a compact hardware emulator for the classical Heisenberg model in statistical physics. The first is the demonstration of spin-diffusion lengths in excess of microns…

Mesoscale and Nanoscale Physics · Physics 2024-07-10 Saleh Bunaiyan , Supriyo Datta , Kerem Y. Camsari

A new way of magnetization switching employing both the spin-transfer torque and the torque by a magnetic field is proposed. The solution of the Landau-Lifshitz-Gilbert equation shows that the dynamics of the magnetization in the initial…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Hirofumi Morise , Shiho Nakamura

Dynamic simulations of spin-transfer and spin-orbit torques are increasingly important for a wide range of spintronic devices including magnetic random access memory, spin-torque nano-oscillators and electrical switching of…

Computational Physics · Physics 2022-11-23 Andrea Meo , Carenza E. Cronshaw , Sarah Jenkins , Amelia Lees , Richard F. L. Evans

Loop Quantum Gravity (LQG) is a non-perturbative attempt at quantization of a classical phase space description of gravity in terms of $SU(2)$ connections and electric fields. As emphasized recently [1], on this phase space, classical…

General Relativity and Quantum Cosmology · Physics 2021-07-07 Madhavan Varadarajan

Precise modeling of the magnetization dynamics of nanoparticles with finite size effects at fast varying temperatures is a computationally challenging task. Based on the Landau-Lifshitz-Bloch (LLB) equation we derive a coarse grained model…

Materials Science · Physics 2019-08-07 Christoph Vogler , Claas Abert , Florian Bruckner , Dieter Suess

Quantum Brownian motion in the strong friction limit is studied based on the exact path integral formulation of dissipative systems. In this limit the time-nonlocal reduced dynamics can be cast into an effective equation of motion, the…

Statistical Mechanics · Physics 2009-11-10 Joachim Ankerhold , Hermann Grabert , Philip Pechukas

Understanding the behaviour of a quantum system coupled to its environment is of fundamental interest in the general field of quantum technologies. It also has important repercussions on foundational problems in physics, such as the process…

Quantum Physics · Physics 2021-11-01 Sapphire Lally , Nicholas Werren , Jim Al-Khalili , Andrea Rocco

The damping of magnetization, represented by the rate at which it relaxes to equilibrium, is successfully modeled as a phenomenological extension in the Landau-Lifschitz-Gilbert equation. This is the damping torque term known as Gilbert…

Other Condensed Matter · Physics 2009-04-01 M. C. Hickey , J. S. Moodera

We discuss the motion of spin in inertial and gravitational fields. The coupling of spin with rotation and the gravitomagnetic field has already been extensively studied; therefore, we focus here on the inertial and gravitational spin-orbit…

General Relativity and Quantum Cosmology · Physics 2013-09-25 Bahram Mashhoon , Yuri N. Obukhov

We study dynamical and thermal effects that are induced in nanoparticle systems by a rotating magnetic field. Using the deterministic Landau-Lifshitz equation and appropriate rotating coordinate systems, we derive the equations that…

Statistical Mechanics · Physics 2016-08-16 S. I. Denisov , T. V. Lyutyy , P. Hänggi , K. N. Trohidou

In the present work, by using the method of accumulation of phase shifts in the rotating frame, the attenuation function S(t) of the NMR signal from an ensemble of spin-bearing particles in a magnetic-field gradient is expressed through the…

Statistical Mechanics · Physics 2018-09-26 Jana Tothova , Vladimir Lisy

A spin dynamics approach has been used to study the behavior of the magnetic spins and the electric pseudo-spins in a 1-D composite multiferroic chain with a linear magneto-electric coupling at the interface. The response is investigated…

Mesoscale and Nanoscale Physics · Physics 2015-10-01 Zidong Wang , Malcolm J. Grimson