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We present a formalism for simulating quantum dynamics of lattice spin-one systems by first introducing local hidden variables and then doing semiclassical (truncated Wigner) approximation in the extended phase space. In this way we exactly…

Quantum Physics · Physics 2016-06-28 Shainen M. Davidson , Anatoli Polkovnikov

We present efficient numerical methods for the simulation of small magnetization oscillations in three-dimensional micromagnetic systems. Magnetization dynamics is described by the Landau-Lifshitz-Gilbert (LLG) equation, linearized in the…

Computational Physics · Physics 2023-01-18 Massimiliano d'Aquino , Riccardo Hertel

Starting from the continuity equation for the magnetization in time-dependent spin-density functional theory, we derive an expression for the effective time-dependent magnetic fields driving the out-of-equilibrium spin dynamics in magnetic…

Mesoscale and Nanoscale Physics · Physics 2017-01-18 Jacopo Simoni , Maria Stamenova , Stefano Sanvito

Using suitable magnetic flux operators established in terms of discrete derivatives leads to quantum-mechanical descriptions of LC-circuits with an external time dependent periodic voltage. This leads to second order discrete Schrodinger…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 C. Micu , E. Papp , L. Aur

Data of the numerical solution of the time-dependent Schr\"odinger equation of a system containing one spin-1/2 particle interacting with a bath of up to 32 spin-1/2 particles is used to construct a Markovian quantum master equation…

Computational Physics · Physics 2016-08-24 P. Zhao , H. De Raedt , S. Miyashita , F. Jin , K. Michielsen

The Bloch equations, which describe spin precession and relaxation in external magnetic fields, can be generalized to include the evolution of polarization tensors of various ranks in arbitrary multipole fields. The derivation of these…

Quantum Physics · Physics 2015-10-23 Hans-Juergen Stoeckmann , Dirk Dubbers

To give a general description of the influences of electric fields or currents on magnetization dynamics, we developed a semiclassical theory for the magnetization implicitly coupled to electronic degrees of freedom. In the absence of…

Mesoscale and Nanoscale Physics · Physics 2018-07-25 Bangguo Xiong , Hua Chen , Xiao Li , Qian Niu

The vector system of linear differential equations for a field with arbitrary fractional spin is proposed using infinite-dimensional half-bounded unitary representations of the $\overline{SL(2,R)}$ group. In the case of $(2j+1)$-dimensional…

High Energy Physics - Theory · Physics 2009-10-28 J. L. Cortes , M. S. Plyushchay

We describe a new method to include magnetic fields into smooth particle hydrodynamics. The derivation of the self-gravitating hydrodynamics equations from a variational principle is discussed in some detail. The non-dissipative magnetic…

Astrophysics · Physics 2008-02-05 S. Rosswog , D. J. Price

We find a modified Bloch equation for the electronic magnetic moment when the magnetic moment explicitly contains a diamagnetic contribution (a magnetic field induced magnetic moment arising from the electronic orbital angular momentum) in…

Soft Condensed Matter · Physics 2009-11-07 B. Segev , Y. B. Band

Non-damped oscillations of the magnetization vector of a ferromagnetic system subject to a spin polarized current and an external magnetic field are studied theoretically by solving the Landau-Lifshitz-Gilbert equation. It is shown that the…

Materials Science · Physics 2007-05-23 P. M. Gorley , P. P. Horley , V. K. Dugaev , J. Barnas , V. R. Vieira

We investigate the spin dynamics in the two-dimensional spin-orbit coupled system subject to an in-plane ($x$-$y$ plane) constant electric field, which is assumed to be turned on at the moment $t=0$. The equation of spin precession in…

Mesoscale and Nanoscale Physics · Physics 2019-06-05 Tsung-Wei Chen , Zhi-Yang Huang , Dah-Wei Chiou

Deterministic dynamical models are discussed which can be described in quantum mechanical terms. In particular, a local quantum field theory is presented which is a supersymmetric classical model. -- The Hilbert space approach of Koopman…

High Energy Physics - Theory · Physics 2007-05-23 Hans-Thomas Elze

The Schr\"odinger equation in the presence of an external electromagnetic field is an important problem in computational quantum mechanics. It also provides a nice example of a differential equation whose flow can be split with benefit into…

Numerical Analysis · Mathematics 2016-04-28 Marco Caliari , Alexander Ostermann , Chiara Piazzola

It is shown that an extended q-deformed $su(2)$ algebra with an extra (``Schwinger '') term can describe Bloch electrons in a uniform magnetic field with an additional periodic potential. This is a generalization of the analysis of Bloch…

High Energy Physics - Theory · Physics 2009-10-30 Kazuo Fujikawa , Harunobu Kubo

The classical Bloch equations of spin magnetization transport is extended to fully time-dependent and highly-nonlinear nonequilibrium spin magnetization quantum distribution function transport (SMQDFT) equations. The relevant variables are…

Quantum Physics · Physics 2012-07-31 F. A. Buot , R. A. Loberternos , R. E. S. Otadoy , D. L. Villarin

Starting from a model of an elastic medium, partial differential equations with the form of the coupled Einstein-Dirac-Maxwell equations are derived. The form of these equations describes particles with mass and spin coupled to…

Other Condensed Matter · Physics 2007-05-23 John M. Baker

We introduce a classical limit of the dynamics of quantum spin systems based on coherent states of SU($N$), where $N$ is the dimension of the local Hilbert space. This approach, that generalizes the well-known Landau-Lifshitz dynamics from…

Strongly Correlated Electrons · Physics 2021-09-08 Hao Zhang , Cristian D. Batista

A novel strategy is proposed for the coupling of field and circuit equations when modeling power devices in the low-frequency regime. The resulting systems of differential-algebraic equations have a particular geometric structure which…

Numerical Analysis · Mathematics 2024-04-25 Herbert Egger , Idoia Cortes Garcia , Vsevolod Shashkov , Michael Wiesheu

Using the Hubbard representation for $SU(2)$ we write the time-evolution operator of a two-level system in the disentangled form. This allows us to map the corresponding dynamical law into a set of non-linear coupled equations. In order to…

Quantum Physics · Physics 2017-08-09 Marco Enriquez , Sara Cruz y Cruz