Открытый доступ
Доступ предоставлен
Только для подписчиков
Том 166, № 2 (2024)
Статьи
САМОСОГЛАСОВАННЫЙ КВАЗИКЛАССИЧЕСКИЙ ПОДХОД К ОПИСАНИЮ ДВИЖЕНИЯ ЧАСТИЦЫ В ДИССИПАТИВНОЙ СРЕДЕ
Аннотация
153-161
КОГЕРЕНТНОЕ УПРАВЛЕНИЕ НАСЕЛЕННОСТЯМИ СВЯЗАННЫХ СОСТОЯНИЙ В КВАНТОВЫХ ЯМАХ ПАРОЙ ПОЛУПЕРИОДНЫХ АТТОСЕКУНДНЫХ ИМПУЛЬСОВ
Аннотация
162-173
КОГЕРЕНТНОЕ РАСПРОСТРАНЕНИЕ ПОЛУЦИКЛОВОГО СВЕТОВОГО ИМПУЛЬСА В ТРЕХУРОВНЕВОЙ СРЕДЕ
Аннотация
174-181
VACUUM BIREFRINGENCE AND DICHROISM IN A STRONG PLANE-WAVE BACKGROUND
Аннотация
In the present study, we consider the effects of vacuum birefringence and dichroism in strong electromagnetic fields. According to quantum electrodynamics, the vacuum state exhibits different refractive properties depending on the probe photon polarization and one also obtains different probabilities of the photon decay via production of electron-positron pairs. Here we investigate these two phenomena by means of several different approaches to computing the polarization operator. The external field is assumed to be a linearly polarized plane electromagnetic wave of arbitrary amplitude and frequency. Varying the probe-photon energy and the field parameters, we thoroughly examine the validity of the locally-constant field approximation (LCFA) and techniques involving perturbative expansions in terms of the external-field amplitude. Within the latter approach, we develop a numerical method based on a direct evaluation of the weak-field Feynman diagrams, which can be employed for investigating more complex external backgrounds. The polarization operator depends on two parameters: classical nonlinearity parameter ξ and the product η = ωq0/m2 of the laser field frequency ω and the photon energy q0 (m is the electron mass). The domains of validity of the approximate techniques in the ξη plane are explicitly identified.
182-193
МОДЕЛИРОВАНИЕ ПРОЦЕССОВ ПОГЛОЩЕНИЯ ЭНЕРГИИ В ВОДЕ ВБЛИЗИ ПОВЕРХНОСТИ ЗОЛОТОЙ НАНОЧАСТИЦЫ ПРИ ОБЛУЧЕНИИ ФОТОНАМИ РЕНТГЕНОВСКОГО ДИАПАЗОНА
Аннотация
194-208
ПРОЦЕСС РАСЩЕПЛЕНИЯ ФОТОНА В СИЛЬНОМ МАГНИТНОМ ПОЛЕ С УЧЕТОМ ВЛИЯНИЯ ПОЗИТРОНИЯ
Аннотация
209-215
EFFECT OF COLOR RANDOMIZATION ON pT BROADENING OF FAST PARTONS IN TURBULENT QUARK-GLUON PLASMA
Аннотация
We analyze the effect of the parton color randomization on pT broadening in the quark-gluon plasma with turbulent color fields. We calculate the transport coefficient for a simplified model of fluctuating color fields in the form of alternating sequential transverse layers with homogenous transverse chromomagnetic fields with random orientation in the SU(3) group and gaussian distribution in the magnitude. Our numerical results show that the color randomization can lead to a sizable reduction of the turbulent contribution to ˆq. The magnitude of the effect grows with increasing ratio of the electric and magnetic screening masses.
216-231
АТОМНЫЙ МЕХАНИЗМ ВЛИЯНИЯ УПРУГИХ ДЕФОРМАЦИЙ ЭПИТАКСИАЛЬНЫХ СЛОЕВ Ge НА ПОВЕРХНОСТИ Si(111) НА ДИФФУЗИЮ АДАТОМОВ Ge
Аннотация
232-237
ВЛИЯНИЕ АМПЛИТУДЫ МАГНИТНОГО ПОЛЯ НА КИНЕТИКУ ПЕРЕМАГНИЧИВАНИЯ МАГНИТНЫХ НАНОЧАСТИЦ
Аннотация
238-245
МАГНИТНЫЕ И СВЕРХПРОВОДЯЩИЕ СВОЙСТВА ДОПИРОВАННЫХ Fe ВЫСОКОТЕМПЕРАТУРНЫХ СВЕРХПРОВОДНИКОВ YBaCuO, СИНТЕЗИРОВАННЫХ ЗОЛЬ–ГЕЛЬ-МЕТОДОМ
Аннотация
246-254
FABRICATION AND STUDY OF THE p − Si/α − Si/Ag MEMRISTOR CROSSBAR ARRAY
Аннотация
We study the formation of the conductive channels in α-Si memristors and demonstrate their operation in the crossbar array. The latter can be utilised as the basic component of the neuromorphic chip tailored for edge computing. The conductive channels in α-Si are formed by the migration of Ag along with Cu ions. Such a channel has switching current-voltage characteristics at high bias, Vbias > 2V, and highly non-linear that at low bias, Vbias < 0.5V. Memristor can be re-programmed to different resistance states with short voltage pulses of amplitude above 2 V. We demonstrate the programming of the memristor crossbar array and its operation in vector-by-matrix multiplication with an 87% accuracy.
255-260
UNTANGLING THE VALLEY STRUCTURE OF STATES FOR INTRAVALLEY EXCHANGE ANISOTROPY IN LEAD CHALCOGENIDES QUANTUM DOTS
Аннотация
We put forward a generalized procedure which allows to restore the bulk-like electron and hole wave functions localized in certain valleys from the wave functions of quantum confined electron/hole states obtained in atomistic calculations of nanostructures. The procedure is applied to the lead chalcogenide quantum dots to accurately extract the intravalley velocity matrix elements and the constants of the effective intravalley Hamiltonian of the exchange interaction for the ground exciton state in PbS and PbSe quantum dots. Our results suggest that intravalley parameters in PbS quantum dots are much more anisotropic than the ones in PbSe. Renormalization of the velocity matrix elements, forbidden band gap, valley and exchange splittings of exciton and exciton binding energy are also calculated.
261-276
BKT TRANSITION IN PHYLLOTAXIS
Аннотация
We explore a two-parameter renormalization group (RG) within the framework of the «energetic approach» introduced by L. Levitov, for the phyllotaxis model. Our focus lies on an equilibrium distribution of strongly repulsive particles situated on the surface of a finite cylinder. We investigate how these particles redistribute as the cylinder undergoes compression along its axis. Specifically, we construct the modular-invariant β-function for the system, which is explicitly expressed in terms of the Dedekind η-function. Utilizing this β-function, we derive equations that describe the RG flow near the bifurcation points, which mark the boundaries between different lattice configurations. By analyzing the structure of these RG equations, we assert the emergence of Berezinskii – Kosterlitz – Thouless transitions under significant cylinder compression.
277-289