arXiv subjects

P. A. Golovinski

Publications and source records attributed to P. A. Golovinski.

At least 19 recordsLinked to original sources

arXiv2021

Quantum states of the Kapitza pendulum

The quantum states of the Kapitza pendulum are described within the effective potential obtained by the method of averaging over the fast oscillations. An analytical estimate of the energy spectrum of stabilized states is given using approximate model potential. For the lowest states of an inverted pendulum, the spectrum is repeduced by the energies of a harmonic oscillator with perturbation theory corrections. Tunneling effect contribution to the energies of resonance states in the double-well effective potential is estimated. The results of numerical simulations of vibrational and rotational spectra of the Kapitza pendulum by the semiclassical method and by the Numerov algorithm are compared.

quant-ph↗

arXiv2020

The pandemic of viruses with a long incubation phase in the small world

A model of the spread of viruses in selected city and in a network of cities is considered, taking into account the delay caused by the long incubation period of the virus. The effect of delay effects is shown in comparison with pandemics without such delay. A temporary asymmetry of the spread of infection has been identified, which means that the time for a pandemic to develop significantly exceeds the time for its completion. Model calculations of the spread of viruses in a network of interconnected large and small cities were carried out, and dynamics features were revealed in comparison with the spread of viruses in a single city, including the possibility of reinfection of megalopolis.

q-bio.OT↗

arXiv2020

Gender Genetic Algorithm in the Dynamic Optimization Problem

A general approach to optimizing fast processes using a gender genetic algorithm is described. Its difference from the more traditional genetic algorithm it contains division the artificial population into two sexes. Male subpopulations undergo large mutations and more strong selection compared to female individuals from another subset. This separation allows combining the rapid adaptability of the entire population to changes due to the variation of the male subpopulation with fixation of adaptability in the female part. The advantage of the effect of additional individual learning in the form of Boldwin effect in finding optimal solutions is observed in comparison with the usual gender genetic algorithm. As a promising application of the gender genetic algorithm with the Boldwin effect, the dynamics of extinguishing natural fires is pointed.

cs.NE↗

arXiv2020

Density of States of an Electron in the Image Field and Blocking Electric Field

The motion of an electron in an image field and a blocking electric field is considered in semiclassical approximation. An exact analytical expression is found for the density of the energy spectrum of states. The dependence of spectral density on energy is obtained in a wide range of electric field strengths. The energy ranges with a qualitatively different structure of the spectrum are determined.

cond-mat.mes-hall↗

arXiv2019

Forced quantum inverted oscillator

New exact and asymptotic results for a quantum inverted oscillator, driven by the variable external force, are presented. To illustrate the advantages of our approach, we applied the obtained propagator to the descriptions of evolution the initial Gaussian wave packet under arbitrary time-dependent force or a δ-pulse action. The alternative problem of tunneling a particle through a parabolic barrier under the influence of a low-frequency harmonic force we solve in the quasistatic approximation. Going to the Heisenberg picture in the Caldeira-Leggett model, we describe the influence of a time-dependent force on an open inverted oscillator. The resulting dynamics is presented in the form of combination the evolution of the average value of a coordinate operator and the stochastic diffusion, being induced the wave packet spreading and the Brownian motion.

quant-ph↗

arXiv2018

A cold electron emission spectrum in a low-frequency laser field

We consider the process of cold emission of electrons from a metal in a strong low-frequency laser field. An expression is obtained for the electron spectrum with allowance for their rescattering at the metal surface as a result of an extension of the Fowler-Nordheim theory and modification of the Simplemen model. The numerically simulated features of the electron spectrum are similar to the ATI spectra for atoms and have the same form as the experimental surface emission dependencies for a metal.

cond-mat.mes-hall↗

arXiv2018

Application of the coupled classical oscillators model to the Fano resonance build-up in a plasmonic nanosystem

We study the excitation dynamics of Fano resonance within the classical model framework of two linear coupled oscillators. An exact solution for the model with a damped harmonic force is obtained. The details of growth a Fano profile under the harmonic excitation is shown. For incident ultra-wideband pulse, the reaction of a system becomes universal and coincides with the time-dependent response function. The results of numerical calculations clarify two alternative ways for experimental measurement of the complete characteristics of a system: direct observation of the system response to a monochromatic force by frequency scanning or recording of time-dependent response to the delta-pulse. As a specific example, time-dependent excitation in a system consisting of a quantum dot and a metal nanoparticle is calculated. Then it is shown the applicability of the extended model of damped oscillators with radiative correction to describe the build-up a plasmon Fano resonance in a scattering of a femtosecond laser pulse by nanoantenna.

physics.optics↗

arXiv2018

Linear build-up of Fano resonance spectral profiles

The build-up dynamics of a continuous spectrum under the action of a weak laser field on a Fano resonance with the use of the pulses with the Lorentz spectrum and ultrashort pulses in the wavelet form is investigated. A dispersion-time excitation dependence of the Fano resonances in a He atom, in an InP impurity semiconductor, in longitudinal optical LO-phonons of a shallow donor exciton in pure ZnO crystals, and in metamaterials are calculated. The numerical simulation of the dynamics has shown time-dependent formation a Fano spectral profile in the systems of different physical natures under the action of ultrashort pulses with attosecond and femtosecond durations.

physics.optics↗

arXiv2016

Nonlinear electron emission under the action of ultrashort laser pulse

The process of nonlinear electron emission from a metal surface under the action of femtosecond laser pulse with moderate intensity $\sim10^{11}$~W/cm$^2$ is considered. One-dimensional model is formulated, taking into account the advantage of the $p$-polarized light in the nonlinear emission. The time dependent Schrodinger equation with fixed equilibrium boundary conditions is solved in the half-space using the Laplace transform technique. The energy spectrum of emitted electrons is obtained, and its dependence on the laser pulse parameters in compare with experimental data is discussed.

cond-mat.mes-hall↗

arXiv2016

Dirac-graphene in slow-light

We obtained exact solutions for the wave function and the Green function in the slow light pulse with the group velocity, consistent with the Fermi velocity in graphene.

physics.optics↗

arXiv2016

Interference at the tunnel ionization from double-center potential

The tunnel ionization of an electron bounded by two delta potentials under the influence of a constant electric field is considered. The equations for the electron current density for two different initial states are obtained. The dependence of the emission current on the orientation of the potential with respect to the field direction and the distance between them is studied. Appropriate conditions for observation essential interference effects are defined.

cond-mat.mes-hall↗

arXiv2015

Reflection of a Broadband Electromagnetic Pulse by Planar Plasma Layer at Normal Incidence

The problem of electromagnetic pulses propagation in plasma was studied in connection with various problems of radio engineering and radar systems. The description of propagation such signals is based on exactly solvable problems for monochromatic waves. We considered two cases: smooth layer and thin sheet. The conditions for different type of reflection are founded.

physics.optics↗

arXiv2015

The broadband pulse diffraction on a half-plane screen and caustic

The diffraction of ultrashort pulse changes its spatial and temporal structure that is crucial for multi-channel communication and location via such pulses. The features of the evolution of broadband pulses discussed for two general problems: diffraction at the edge of a flat absorbing screen and the field near a simple caustic. The basic equations are formulated for spatial distribution of the pulse field after the screen in the spectral and time domain. Calculations of pulse diffraction for different wave shapes and comparison of results are presented. We obtain an integral representation for pulse field with arbitrary initial form near a caustic and analyze the results for different waveforms.

physics.optics↗

arXiv2015

Diffraction of Ultrashort Pulse on a Nanoscale Conductive Cone

Surface plasmon polariton is collective oscillation of the free electrons at metal dielectric interface. As a wave phenomenon, surface plasmon polaritons can be focused using appropriate excitation geometry of metallic structures. We theoretically demonstrate the possibility of controlling nanoscale short pulse superfocusing based on the generation of radially polarized surface plasmon polariton mode of conical metallic tip. Numerical simulation for femtosecond pulse propagation along a silver nano-needle is discussed. The spatial distribution for a near field strongly depends on a linear chirp of the laser pulse which can partially compensate the wave dispersion. Field distribution is calculated for different chirp values, opening angles and distances. For a pulse with a negative chirp, pulse duration becomes shorter with amplification ~40.

physics.optics↗

arXiv2015

The response of an electron in the image potential on the external steady fields

The exact wave functions, which describe the states of an electron, bound in the image potential, and the magnetic field, which is perpendicular to surface of a metal, are obtained. The correction terms to the energy of an electron in the first order of the perturbation theory with respect to the interaction with the external electric field are calculated. The possibility of experimental measurement of a local electric field by the level shift is analyzed.

quant-ph↗

arXiv2015

Influence of center distance on high harmonic generation

The nonlinear ionization with accompanied photorecombination on closely located center has been considered. The radiation spectrum has been calculated in the frame of the Lewenstein-Corkum approach. The dependence of radiation on the distance between ionization point and the recombination center, and the frequency and laser field strength has been investigated.

physics.atom-ph↗

arXiv2014

Control of excitation transfer in coupled quantum dots by a nonresonant laser pulse

We study theoretically fast transfer of excitons between pairs of coupled quantum dots driven by the optical Stark effect that is produced by a short nonresonant laser pulse. The Schrödinger equation, in which the relative position of energy levels of quantum dot subsystems is time-dependent, is solved numerically. Computer simulation shows a way to achieve efficient excitation transfer by the action of a picosecond laser pulse with a rectangular envelope function.

cond-mat.mes-hall↗

arXiv2013

Radiation of the Tunnel Electron on Secondary Center of Recombination

We discuss the photon emission that occurs due to the radiative recombination of an electron on a nearby center after tunneling ionization. The model of an active electron is used, and analytical solution to three-dimensional problem is obtained. The dependence of the photon emission from a distance between centers of ionization and a recombination, and also the electric field orientation are investigated. The formulas for probability of recombination radiation are derived.

cond-mat.mes-hall↗