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Related papers: Quantum diffusion

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Distribution functions defined in accord with the quantum theory of measurement are combined with results obtained from the quantum Langevin equation to discuss decoherence in quantum Brownian motion. Closed form expressions for wave packet…

Quantum Physics · Physics 2009-11-10 G. W. Ford , J. T. Lewis , R. F. O'Connell

We propose an approach that allows to systematically take into account gravity in quantum particle physics. It is based on quantum field theory and the general principle of relativity. These are used to build a model for quantum particles…

High Energy Physics - Theory · Physics 2022-04-14 Viacheslav A. Emelyanov

The atmospheric turbulence is the main factor that influences quantum properties of propagating optical signals and may sufficiently degrade the performance of quantum communication protocols. The probability distribution of transmittance…

Quantum Physics · Physics 2018-07-06 D. Vasylyev , W. Vogel , A. A. Semenov

Particle dynamics are investigated in plasma turbulence, using self-consistent kinetic simulations, in two dimensions. In steady state, the trajectories of single protons and proton-pairs are studied, at different values of plasma "beta"…

Plasma Physics · Physics 2016-08-31 S. Servidio , C. T. Haynes , W. H. Matthaeus , D. Burgess , V. Carbone , P. Veltri

Quantum mechanics asserts that a wave packet must inevitably spread as time progresses since the dispersion relation for the quantum waves is assumed to be quadratic in the momentum k. However, this assumption does not consider the standard…

Quantum Physics · Physics 2007-05-23 S. Bruce

We study diffusion processes in anomalous spacetimes regarded as models of quantum geometry. Several types of diffusion equation and their solutions are presented and the associated stochastic processes are identified. These results are…

High Energy Physics - Theory · Physics 2015-03-20 Gianluca Calcagni

Rotating turbulence is ubiquitous in nature. Previous works suggest that such turbulence could be described as an ensemble of interacting inertial waves across a wide range of length scales. For turbulence in macroscopic quantum…

The transport properties of disordered systems are known to depend critically on dimensionality. We study the diffusion coefficient of a quantum particle confined to a lattice on the surface of a tube, where it scales between the 1D and 2D…

Mesoscale and Nanoscale Physics · Physics 2016-05-18 Chern Chuang , Chee Kong Lee , Jeremy M. Moix , Jasper Knoester , Jianshu Cao

We study numerically quantum diffusion of a particle on small-world networks by integrating the time-dependent Schr\"odinger equation with a localized initial state. The participation ratio, which corresponds to the number of visited sites…

Disordered Systems and Neural Networks · Physics 2007-05-23 Beom Jun Kim , H. Hong , M. Y. Choi

The time dependence of one-dimensional quantum mechanical probability densities is presented when the potential in which a particle moves is suddenly changed, called a quench. Quantum quenches are mainly addressed but a comparison with…

Quantum Physics · Physics 2024-06-18 K. Schönhammer

Two recent studies have presented new information relevant to the transition from quantum behavior to classical behavior, and related this to parameters characterizing the universe as a whole. The present study based on a separate approach…

General Physics · Physics 2007-06-12 C. L. Herzenberg

Molecular hydrogen is a fascinating candidate for quantum fluid showing bosonic and fermionic superfluidity. We have studied diffusion dynamics of thin films of H$_2$, HD and D$_2$ adsorbed on a glass substrate by measurements of…

Strongly Correlated Electrons · Physics 2019-12-18 Takahiko Makiuchi , Katsuyuki Yamashita , Michihiro Tagai , Yusuke Nago , Keiya Shirahama

We report the prediction of temperature-dependent diffusion coefficients of interstitial hydrogen, deuterium, and tritium atoms in $\alpha$-Ti using transition state theory. The microscopic parameters in the pre-factor and activation energy…

Materials Science · Physics 2015-06-15 Yong Lu , Ping Zhang

By a generalization of the Hopfield model, we construct a microscopic Lagrangian describing a dielectric medium with dispersion and dissipation. This facilitates a well-defined and unambiguous $\textit{ab initio}$ treatment of quantum…

Quantum Physics · Physics 2021-01-04 Sascha Lang , Ralf Schützhold , William G. Unruh

For a quantum-mechanically spread-out particle we investigate a method for determining its arrival time at a specific location. The procedure is based on the emission of a first photon from a two-level system moving into a laser-illuminated…

Quantum Physics · Physics 2009-11-07 J. A. Damborenea , I. L. Egusquiza , G. C. Hegerfeldt , J. G. Muga

The motion of a quantum particle hopping on a simple cubic lattice under the influence of thermal noise and of a static random potential is expected to be diffusive, i.e., the particle is expected to exhibit `quantum Brownian motion', no…

Mathematical Physics · Physics 2017-09-22 Jürg Fröhlich , Jeffrey Schenker

Thermodynamical equilibrium is considered as an effect of quantum entangling of the vacuum state of a system. An explicit mathematical model of multi- particle entangled pure quantum states is developed and analyzed. In the framework, the…

Quantum Physics · Physics 2007-05-23 A. Yu. Bogdanov , Yu. I. Bogdanov , K. A. Valiev

Classical-like formulas are given in order to evaluate thermal averages of observables belonging to a quantum nonlinear system with dissipation described by the Caldeira-Leggett model [Phys. Rev. Lett. 46, 211 (1981); Ann. Phys. (N.Y.) 149,…

Statistical Mechanics · Physics 2009-10-30 Alessandro Cuccoli , Andrea Rossi , Valerio Tognetti , Ruggero Vaia

The rigorous analytical calculation of the diffusion coefficient is performed for the chaotic motion of a particle in a set of longitudinal waves with random phases and large amplitudes (~ A). A first step proves the existence of a…

Plasma Physics · Physics 2007-05-23 D. F. Escande , Y. Elskens

What is the quantum system? Consider the wavefunction of the electron, what we call single particle wave-function and assume that it contains N wave packets. If we pass all the wave packets through an electric field, all are deflected, as…

Quantum Physics · Physics 2021-07-14 Sofia Wechsler
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