arXiv subjects

Pavel Golovinski

Publications and source records attributed to Pavel Golovinski.

3 recordsLinked to original sources

arXiv2026

Electron-laser vacuum breakdown in head-on collision of relativistic electrons with intense laser pulse

The phenomenon of electron-laser vacuum breakdown is the multiple cascade production of electron-positron pairs in head-on collision of a beam of relativistic electrons with an intense laser pulse. This effect was first predicted by the author in 1996 [1] and further developed in [2]. In the present paper, an analytical expression for the total number of produced particles is obtained using the generalized Heitler model. The model results are shown to be in good agreement with the estimates of the pioneering works. An analysis of modern laser facilities (ELI, XCELS, European XFEL, Russian projects) is carried out and estimates of the expected effects are given. At ELI and XCELS class facilities, the quantum nonlinearity parameter can reach 60--150, corresponding to the deeply nonlinear QED regime with multiplicity up to 100 particles per seed electron. Experimental confirmation of the effect is expected in the coming years.

physics.optics↗

arXiv2026

Influence of Disorder on Exciton Transfer in a Quantum Dot Chain with Short-Range Interaction and a Side-Coupled Defect

This paper considers the propagation of excitons in linear chains of QDs with a side defect, located on a dielectric substrate. This configuration is suitable for spatially selective excitation of the system by pulsed optical radiation through the side defect. The dynamics of excitation in the chain is governed by structural disorder, caused by technological variations in the parameters of the QDs themselves and their mutual arrangement. To describe the quantum properties of excitons in the QD chain, a model Hamiltonian is used, taking into account the coupling of neighboring QDs due to dipole-dipole interaction. The localization of stationary states is calculated depending on the magnitude of disorder and the chain length. A criterion is introduced that determines the boundaries of the phase transition from the localized to the delocalized excitation phase. The dynamics of exciton transfer along the QD chain is calculated depending on its length and degree of disorder for linear excitation of the system by a laser pulse. It is shown that dynamic localization emerging in the system corresponds to the stationary localization properties of the states of the chain with a side defect.

cond-mat.mes-hall↗

arXiv2020

Premelting fluctuations

A model of the premelting fluctuations is proposed, based on the Landau mean field theory applied to a first-order phase transition. Using the thermodynamic potential, the nonlinear Langevin equation for the order parameter is formulated, which describes the dynamics of the phase transition considering microscopic thermal fluctuations. The origin of the low-frequency fluctuations, associated with a switching in a bistable system under the influence of a thermal noise, is shown. Analytical two-scale model of the premelting fluctuations is developed, with characteristic frequent small-amplitude fluctuations of chaotic motion in the vicinity of potential minima and rarer large fluctuations due to solid-liquid transitions. Based on the numerical simulation of the solutions to the stochastic differential equation, both the dynamics of the order parameter fluctuations and their spectrum are obtained. The model qualitatively reproduces experimental spectrum of isothermal fluctuations.

cond-mat.mes-hall↗