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By revising the application of the open quantum system approach to the early universe and extending it to the conditions beyond the Markovian approximation, we obtain a new non-Markovian quantum Boltzmann equation. Throughout the paper, we…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-04 Moslem Zarei , Nicola Bartolo , Daniele Bertacca , Angelo Ricciardone , Sabino Matarrese

Non-Hermitian physics has recently attracted much attention in optics and photonics. Less explored is non-Hermitian magnonics that provides opportunities to take advantage of the inevitable dissipation of magnons or spin waves in magnetic…

Lattice gases in the strongly correlated regime have been proven to simulate quantum magnetic models under certain conditions: the mapping of the double-well system onto the Lipkin-Meshkov-Glick spin model is a paradigmatic case. A suitable…

Quantum Gases · Physics 2016-12-28 A. Gallemí , G. Queraltó , M. Guilleumas , R. Mayol , A. Sanpera

The excitation of high-frequency short-wavelength spin waves is a challenge limiting the application of these propagating magnetization disturbances in information processing systems. We propose a method of local excitation of the…

Mesoscale and Nanoscale Physics · Physics 2021-06-22 Pawel Gruszecki , Igor L. Lyubchanskii , Konstantin Y. Guslienko , Maciej Krawczyk

Collective excitations both for spin- and charge-channels are investigated in incommensurate spin density wave (or stripe) states on two-dimensional Hubbard model. By random phase approximation, the dynamical susceptibility \chi(q,\omega)…

Strongly Correlated Electrons · Physics 2009-10-31 Eiji Kaneshita , Masanori Ichioka , Kazushige Machida

Spin waves (SW) are the excitation of the spin system in a ferromagnetic condensed matter body. They are collective excitations of the electron system and, from a quasi-classical point of view, can be understood as a coherent precession of…

Mesoscale and Nanoscale Physics · Physics 2019-01-23 A. V. Chumak , H. Schultheiss

The cornerstone of Boltzmann-Gibbs ($BG$) statistical mechanics is the Boltzmann-Gibbs-Jaynes-Shannon entropy $S_{BG} \equiv -k\int dx f(x)\ln f(x)$, where $k$ is a positive constant and $f(x)$ a probability density function. This theory…

Physics and Society · Physics 2009-11-11 Silvio M. Duarte Queiros , Celia Anteneodo , Constantino Tsallis

Magnetic noise spectroscopy provides a noninvasive probe of spin dynamics in magnetic materials. We consider two-dimensional magnetically ordered insulators with magnon excitations, especially those supporting long-distance magnon…

Mesoscale and Nanoscale Physics · Physics 2022-05-25 Haocheng Fang , Shu Zhang , Yaroslav Tserkovnyak

We have discussed dynamical properties of the Tsallis entropy and the generalized Fisher information in nonextensive systems described by the Langevin model subjected to additive and multiplicative noise. Analytical expressions for the…

Statistical Mechanics · Physics 2009-11-13 Hideo Hasegawa

The entropy stabilized oxide Mg$_{0.2}$Co$_{0.2}$Ni$_{0.2}$Cu$_{0.2}$Zn$_{0.2}$O exhibits antiferromagnetic order and magnetic excitations, as revealed by recent neutron scattering experiments. This observation raises the question of the…

Disordered Systems and Neural Networks · Physics 2021-09-29 Tom Berlijn , Gonzalo Alvarez , David S. Parker , Raphaël P. Hermann , Randy S. Fishman

Starting from kinetic theory description of massive spin-1/2 particles in presence of magnetic field, equations for relativistic dissipative non-resistive magnetohydrodynamics are obtained in the small polarization limit. We use a…

We introduce a topological gauge vector potential which influences spin wave excitations over arbitrary non-uniform, slowly moving magnetization distribution. The time-component of the gauge potential plays a principal role in magnetization…

Other Condensed Matter · Physics 2009-07-15 Konstantin Y. Gusliyenko , Gloria R. Aranda , Julian M. Gonzalez

The nonextensivity in a non-isothermal plasma system with the Coulombian long-range interactions is studied in the framework of Tsallis statistics. We present for first time a mathematical expression of the nonextensive parameter q based on…

Statistical Mechanics · Physics 2015-08-10 Jiulin Du

Collective excitations in magnetic materials can be investigated by means of inelastic neutron scattering. We show that this experimental method gives access to the complete spectrum of magnetic fluctuations through the energy- and…

Strongly Correlated Electrons · Physics 2007-05-23 B. Roessli , P. Böni

Waves with different symmetries exist in two-component Bose-Einstein condensates (BECs) whose dynamics is described by a system of coupled Gross-Pitaevskii (GP) equations. A first type of waves corresponds to excitations for which the…

Quantum Gases · Physics 2016-12-22 A. M. Kamchatnov , Y. V. Kartashov , P. -É. Larré , N. Pavloff

Magnons, the quanta of collective spin excitations in magnetically ordered materials, have distinct properties that make them uniquely appealing for quantum information applications. They can have ultra-small wavelengths down to the…

Spatial intermittency in fully developed turbulence is an established feature of astrophysical plasma fluctuations and in particular apparent in the interplanetary medium by in situ observations. In this situation the classical…

Astrophysics · Physics 2017-08-02 M. P. Leubner , Z. Voros , W. Baumjohann

In this paper, nonlinear equations describing one-dimensional non-Heisenberg ferromagnetic model are studied by use of generalized coherent states in a real parameterization. Also dissipative spin wave equation for dipole and quadruple…

Strongly Correlated Electrons · Physics 2012-01-17 Khikmat Kh. Muminov , Yousef Yousefi

We present a derivation using kinetic wave theory of the two-dimensional empirical Garrett--Munk spectrum for ocean internal waves, valid at all frequencies including near-inertial frequencies. This is based directly on the governing…

Fluid Dynamics · Physics 2026-01-06 Michal Shavit , Oliver Bühler , Jalal Shatah

A general three-dimensional noncommutative quantum mechanical system mixing spatial and spin degrees of freedom is proposed. The analogous of the harmonic oscillator in this description contains a magnetic dipole interaction and the ground…

High Energy Physics - Theory · Physics 2009-10-06 H. Falomir , J. Gamboa , J. Lopez-Sarrion , F. Mendez , P. A. G. Pisani