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Yu. E. Kuzovlev

Publications and source records attributed to Yu. E. Kuzovlev.

At least 19 recordsLinked to original sources
arXiv2019

Kinetics, pseudo-kinetics, uncertainty principle and quantum 1/f noise

1/f noise at arbitrary low frequences is the way of existence of irreversibility in thermal motion governed by reversible laws of mechanics. This statement not once was confirmed in statistical mechanics beyond its traditional kinetical roughenings. Here we point out that in case of quantum statistical mechanics in principle it is sufficient to avoid such the roughening as the "Fermi golden rule". This means taking into account the time-energy uncertainty principle (time-frequency one in classical limit) and thus uncertainties in characteristics of real collisions and scatterings of particles and/or quanta. We consider the resulting "pseudo-kinetics" and demonstrate how it produces quantum 1/f-noise

cond-mat.stat-mech↗
arXiv2017

On 1/f-noise of electron in phonon field

Exact propagator of density matrix of particle (electron) under influence of thermal vibrations of its medium (phonons) is treated in simplest approximation beyond the Fermi's golden rule. It is shown that uncertainties \,$\sim\h/t$\, in energy exchanges with the medium give rise to flicker fluctuations in rate of diffusion (diffusivity) of the particle

cond-mat.stat-mech↗
arXiv2015

On true relaxation statistics in gases

By example of a particle interacting with ideal gas, it is shown that statistics of collisions in statistical mechanics at any degree of the gas rarefaction qualitatively differs from that conjugated with Boltzmann's hypothetical molecular chaos and kinetic equation. In reality, probability of the particle collisions in itself is random, which results in power-law asymptotic of the particle velocity relaxation. An estimate of its exponent is suggested basing on simple kinematic reasonings

cond-mat.stat-mech↗
arXiv2015

Why the nature needs 1/f-noise

Low-frequency 1/f-noise occurs at all levels of the nature organization and became an actual factor of nanotechnologies, but in essence it remains misunderstood by its investigators. Here, once again it is pointed out that such the state of affairs may be caused by uncritical application of probability theory notions to physical random phenomena, first of all the notion of "independence". It is shown that in the framework of statistical mechanics no medium could provide an inner wandering particle with quite certain value of diffusivity and mobility, thereby producing flicker fluctuations of these quantities. This is example of realization of universal 1/f-noise origin in many-particle systems: dependence of time progress of any particular relaxation or transport process on the whole system's detailed initial microstate

cond-mat.stat-mech↗
arXiv2014

Hard-ball gas as hard nut of statistical mechanics (why mathematicians missed 1/f-noise there)

We continue discussion of hard-ball models of statistical mechanics, by example of random walk of hard ball immersed into equlibrium ideal gas. Our goal is to highlight decisive role of specific phase-space subsets, despite their vanishingly smaall Lebesgue measures under the Boltzmann-Grad limit. The "art of draining" such subsets in conventional mathematical constructions resulted in loss of so principal property of many-particle systems as 1/f-noise in diffusivities, mobilities and other transport and relaxation rates. We suggest new approaches to formulation and analysis of evolution equations for hierarchy of probability distribution functions of infinite hard-ball systems, thus further overcoming prejudices of Boltzmannian kinetics and mistakes of its modern adepts

cond-mat.stat-mech↗
arXiv2013

Exercises in simplest dynamical random walk, or Quantum path integral approach to true diffusion law and 1/f noise of classical particle interacting with ideal gas

Statistics of classical Hamiltonian random walk of particle colliding with atoms of ideal gas is considered from viewpoint of earlier suggested exact pseudo-quantum path integral representation of the problem, and qualitative agreement is demostrated between results of an naturally arising simple approximation of this integral and results obtained by formally different methods, thus in a new fashion showing inevitability of scaleless 1/f-type fluctuations in rates of molecular Brownian motions and other dynamical transport and evolution processes.

cond-mat.stat-mech↗
arXiv2013

Quantum generalized fluctuation-dissipation relations in terms of time-distributed observations

New formulations of quantum generalized fluctuation-dissipation relations in terms of characteristic and probabilistic functionals of continuous observations are suggested and discussed. It is shown that control of entropy production in quantum system turns any measurement in it to a source of its extra perturbations, and because of this effect relations between probabilities of mutually time-reversed processes become definitely non-local in their functional space

cond-mat.stat-mech↗
arXiv2013

Fluctuation-dissipation relations: achievements and misunderstandings

We discuss the "generalized fluctuation-dissipation relations (theorems)" for the first time suggested by us in 1977-1984 as statistical-thermodynamical consequences of time symmetry (reversibility) of microscopic dynamics. It is shown, in particular, that our old results in essence contain, as alternative formulations or special cases, various similar relations, including the "fluctuation theorems", what appeared after 1990.

cond-mat.stat-mech↗
arXiv2013

Hamiltonian Brownian motion in Gaussian thermally fluctuating potential. I. Exact Langevin equations, invalidity of Marcovian approximation, common bottleneck of dynamic noise theories, and diffusivity/mobility 1/f noise

Dynamical random walk of classical particle in thermodynamically equilibrium fluctuating medium, - Gaussian random potential field, - is considered in the framework of explicit stochastic representation of deterministic interactions. We discuss corresponding formally exact Langevin equations for the particle's trajectory and show that Marcovian kinetic equation approximation to them is inadequate, - even (and especially) in case of spatially-temporally short-correlated field, - since ignores such actual effects of exponential instability of the trajectory (in respect to small perturbations) as scaleless low-frequency diffusivity/mobility fluctuations (and other excess degrees of randomness) reflected by third-, fourth- and higher-order long-range irreducible statistical correlations. We try to catch the latter, - squeezing through typical theoretical narrow bottleneck, - with the help of an exact relationship between the instability and diffusivity statistical characteristics, along with standard analytical d approximations. The result is quasi-static diffusivity fluctuations which generally are comparable with mean value of diffusivity and disappear in the limit of infinitely large medium's correlation length or infinitely small correlation time only, in agreement with the previously suggested theorem on fundamental 1/f noise.

cond-mat.stat-mech↗
arXiv2012

Brownian particle in ideal gas: explicit density expansions, conditional probabilities, and amusing properties of molecular chaos

Explicit density expansions of non-equilibrium probability distribution functions for molecular Brownian particle in ideal gas are obtained in original form what visually implies (is exact solution to) the previously established dynamical virial relations. Role of these relations in unbiased analysis of molecular chaos properties in many-particle statistical mechanics, including the mobility 1/f noise, is newly investigated in clear terms of conditional probabilities and averages.

cond-mat.stat-mech↗
arXiv2012

Quantum Brownian motion and a theorem on fundamental 1/f noise

We consider quantum Hamiltonian systems composed of mutually interacting "dynamical subsystem" with one or several degrees of freedom and "thermostat" with arbitrary many degrees of freedom, under assumptions that the interaction ensures irreversible behavior of the dynamical subsystem, that is finite diffusivities of its coordinates in thermodynamically equilibrium state and finite drift velocities and mobilities in non-equilibrium steady state in presence of external driving forces. It is shown that, nevertheless, regardless of characteristics of the interaction, the diffusivity and mobility have no certain values but instead vary from one observation to another and undergo 1/f-type or flicker-type low-frequency fluctuations.

cond-mat.stat-mech↗
arXiv2012

Magnetostatic Spin Waves and Magnetic-Wave Chaos in Ferromagnetic Films. III. Numeric Simulations of Microwave-Band Magnetic Chaos, Its Synchronization and Application to Secure Communication

Selected results of original numeric simulations of non-linear magnetostatic spin waves and microwave-frequency magnetic chaos in ferrite films are expounded, as third part of the work whose first two parts are recent arXive preprints 1204.0200 and 1204.2423 . Especially we consider crucial role of parametric processes in creating the chaos and simultaneously obstacles to its synchronization, and examine some possibilities of good enough synchronization (to an extent allowing its use for direct secure communication in microwave band).

cond-mat.other↗
arXiv2012

Magnetostatic spin waves and magnetic-wave chaos in ferromagnetic films. II. Numerical simulations of non-linear waves

A method and some results of numeric simulations of magnetostatic spin waves in ferromagnetic films are exponded, in comparison with the theory earlier presented in arXiv preprint 1204.0200. In particular, roles of films finiteness (edges) and defects in formation of linear and non-linear magnetostatic wave patterns, excitation and evolution of two-dimensional solitons, and chaotic non-linear ferromagnetic resonance are considered.

cond-mat.other↗
arXiv2012

Magnetostatic spin waves and magnetic-wave chaos in ferromagnetic films. I. Theory of magnetostatic waves in plates under arbitrary anisotropy and external fields

General phenomenological theory of magnetic spin waves in ferromagnetic media is originally reformulated and applied to analysis of magnetostatic waves in films and plates with arbitrary nisotropy under arbitrary external field. Exact expressions are derived for propagator of linear waves between antennae (inductors) and mutual impedances of antennae, and exact unified dispersion equation is obtained which describes all types of magnetostatic wave eigen-modes. Characteristic frequencies (spectra) and some other important properties of main modes are analytically considered and graphically illustrated. Besides, several aspects of non-linear excitations and magnetic-wave chaos are discussed, including two-dimensional "non-linear Schrodinger equations" for magnetostatic wave packets and envelope solitons.

cond-mat.other↗
arXiv2012

Dynamical virial relations and invalidity of the Boltzmann kinetic equation

A sequence of exact relations is found which connect one- and many-particle time-dependent distribution functions of low-density gas with their derivatives in respect to mean density. It is shown that, at least in the context of spatially non-uniform gas evolutions, these relations forbid the "molecular chaos propagation" and imply inapplicability of the Boltzmann kinetic equation even under the Boltzmann-Grad limit and regardless of degree of the non-uniformity.

cond-mat.stat-mech↗