scholarly journals Кулоновские плазмон-экситоны в планарных наноструктурах металл-полупроводник

2021 ◽  
Vol 63 (4) ◽  
pp. 527
Author(s):  
В.А. Кособукин
Keyword(s):  
Quantum Well ◽  
Surface Plasmons ◽  
Metal Film ◽  
Equations Of Motion ◽  
Normal Modes ◽  
Harmonic Oscillators ◽  
Two Dimensional ◽  
Coupled Harmonic Oscillators ◽  
Dipole Force ◽  
Two Peaks

A theory of Coulomb (non-radiative) plasmons-excitons in a semiconductor with adjacent quantum well and ultrathin metal film is presented. The equations of motion are formulated for the polarization waves of surface plasmons and quasi-two-dimensional excitons with taking account of Coulomb interaction between them. Within a model of coupled harmonic oscillators, solved are the problems of Coulomb plasmon, exciton and plasmon-exciton excitations in the presence of an external dipole force. The coupling contant is calculated for plasmon-excitons, their optical spectra are investigated, and the relative contributions of plasmons and excitons to the normal modes are found. It is concluded that near the resonance between plasmon and exciton the spectrum of plasmon-exciton excitations consists of two peaks whose behavior in passing through the resonance shows the signs of anti-crossing effect (repulsion of frequencies).

scholarly journals Двумерные кулоновские плазмон-экситоны: релаксация возбуждений

2021 ◽  
Vol 63 (8) ◽  
pp. 1157
Author(s):  
В.А. Кособукин
Keyword(s):  
Near Field ◽  
Equations Of Motion ◽  
Harmonic Oscillators ◽  
Classical Electrodynamics ◽  
Two Dimensional ◽  
Linear Vibration ◽  
Coupled Harmonic Oscillators ◽  
Vibration Theory ◽  
Mechanical Oscillators ◽  
External Polarization

A theory is developed for the relaxation of two-dimensional non-radiative (Coulomb) plasmon-excitons in thin closely located layers of a metal and a semiconductor. In the framework of classical electrodynamics, the equations of motion are formulated for the polarization waves of non-radiative plasmons and excitons with taking into account the Coulomb coupling and the near-field of external polarization. In the model of coupled harmonic oscillators represented by the polarization fields of excitations, the problem of relaxation is solved for Coulomb plasmons, excitons and plasmon-excitons. It is shown that the two dispersion branches of normal plasmon-exciton modes undergo anticrossing (mutual repulsion) at the resonance between plasmon and exciton. With dissipative damping and power interchange between the excitations taken into account, the process of plasmon-exciton relaxation depending on time is investigated. The theory displays the principal analogies between dynamics of plasmon-excitons and of excitations in other objects of linear vibration theory, such as mechanical oscillators, resonant electric chains, etc.

scholarly journals Lattice vibrations with Rayleigh dissipation

2000 ◽  
Vol 42 (2) ◽  
pp. 244-253 ◽  
Author(s):  
J. N. Boyd ◽  
P. N. Raychowdhury
Keyword(s):  
Natural Frequencies ◽  
Linear Array ◽  
Equations Of Motion ◽  
Dissipation Function ◽  
Lagrangian Formulation ◽  
Harmonic Oscillators ◽  
Lattice Vibrations ◽  
Circular Array ◽  
Coupled Harmonic Oscillators ◽  
Symmetry Coordinates

AbstractWe approximate a linear array of coupled harmonic oscillators as a symmetric circular array of identical masses and springs. The springs are taken to possess mass distributed along their lengths. We give a Lagrangian formulation of the problem of finding the natural frequencies of oscillation for the array. Damping terms are included by means of the Rayleigh dissipation function. A transformation to symmetry coordinates as determined by the group of rotations of the circle uncouples the equations of motion.

Thermal effect in the resonance fluorescence of a two-level system

1991 ◽  
Vol 69 (11) ◽  
pp. 1367-1372
Author(s):  
C. H. A. Fonseca ◽  
L. A. Amarante Ribeiro
Keyword(s):  
Equations Of Motion ◽  
Normal Modes ◽  
Thermal Fluctuations ◽  
Harmonic Oscillators ◽  
Thermal Bath ◽  
Resonance Fluorescence ◽  
Level System ◽  
Near Resonance ◽  
Intensity Correlation Function ◽  
Heisenberg Equations

The damped two-level system, driven by a strong incident classical field near resonance frequency is subjected to the effect of thermal fluctuations. To simulate the thermal bath we introduce a large system of harmonic oscillators that represents the normal modes of the thermal radiation field. From the Heisenberg equations of motion we calculate the power spectrum of the scattered field and the intensity correlation function. The results show that the presence of the bath dramatically modifies the light scattered by the two-level system when compared with the case without a thermal bath.

scholarly journals On the appearance of internal wave attractors due to an initial or parametrically excited disturbance

2013 ◽  
Vol 714 ◽  
pp. 283-311 ◽  
Author(s):  
Janis Bajars ◽  
Jason Frank ◽  
Leo R. M. Maas
Keyword(s):  
Gravity Waves ◽  
Normal Modes ◽  
Internal Gravity Waves ◽  
Harmonic Oscillators ◽  
Two Dimensional ◽  
Boussinesq Model ◽  
Resonant Modes ◽  
The Waves ◽  
Shaped Domain ◽  
Parametric Forcing

AbstractIn this paper we solve two initial value problems for two-dimensional internal gravity waves. The waves are contained in a uniformly stratified, square-shaped domain whose sidewalls are tilted with respect to the direction of gravity. We consider several disturbances of the initial stream function field and solve both for its free evolution and for its evolution under parametric excitation. We do this by developing a structure-preserving numerical method for internal gravity waves in a two-dimensional stratified fluid domain. We recall the linearized, inviscid Euler–Boussinesq model, identify its Hamiltonian structure, and derive a staggered finite difference scheme that preserves this structure. For the discretized model, the initial condition can be projected onto normal modes whose dynamics is described by independent harmonic oscillators. This fact is used to explain the persistence of various classes of wave attractors in a freely evolving (i.e. unforced) flow. Under parametric forcing, the discrete dynamics can likewise be decoupled into Mathieu equations. The most unstable resonant modes dominate the solution, forming wave attractors.

scholarly journals A Liouville’s Formula for Systems with Reflection

Mathematics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 866
Author(s):  
Santiago Codesido ◽  
F. Adrián F. Tojo
Keyword(s):  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Linear Systems ◽  
Harmonic Oscillators ◽  
Two Dimensional ◽  
Coupled Harmonic Oscillators ◽  
Systems Of Odes

In this work, we derived an Abel–Jacobi–Liouville identity for the case of two-dimensional linear systems of ODEs (ordinary differential equations) with reflection. We also present a conjecture for the general case and an application to coupled harmonic oscillators.

Two-dimensional leaps in near-critical flow over isolated orography

2005 ◽  
Vol 461 (2064) ◽  
pp. 3747-3763 ◽  
Author(s):  
E.R Johnson ◽  
G.G Vilenski
Keyword(s):  
Unsteady Flow ◽  
Equations Of Motion ◽  
Fold Increase ◽  
Flow Speed ◽  
Two Dimensional ◽  
Subcritical Flow ◽  
One Dimensional ◽  
Petviashvili Equation ◽  
Lee Wave ◽  
Supercritical Flows

This paper describes steady two-dimensional disturbances forced on the interface of a two-layer fluid by flow over an isolated obstacle. The oncoming flow speed is close to the linear longwave speed and the layer densities, layer depths and obstacle height are chosen so that the equations of motion reduce to the forced two-dimensional Korteweg–de Vries equation with cubic nonlinearity, i.e. the forced extended Kadomtsev–Petviashvili equation. The distinctive feature noted here is the appearance in the far lee-wave wake behind obstacles in subcritical flow of a ‘table-top’ wave extending almost one-dimensionally for many obstacles widths across the flow. Numerical integrations show that the most important parameter determining whether this wave appears is the departure from criticality, with the wave appearing in slightly subcritical flows but being destroyed by two-dimensional effects behind even quite long ridges in even moderately subcritical flow. The wave appears after the flow has passed through a transition from subcritical to supercritical over the obstacle and its leading and trailing edges resemble dissipationless leaps standing in supercritical flow. Two-dimensional steady supercritical flows are related to one-dimensional unsteady flows with time in the unsteady flow associated with a slow cross-stream variable in the two-dimensional flows. Thus the wide cross-stream extent of the table-top wave appears to derive from the combination of its occurrence in a supercritical region embedded in the subcritical flow and the propagation without change of form of table-top waves in one-dimensional unsteady flow. The table-top wave here is associated with a resonant steepening of the transition above the obstacle and a consequent twelve-fold increase in drag. Remarkably, the table-top wave is generated equally strongly and extends laterally equally as far behind an axisymmetric obstacle as behind a ridge and so leads to subcritical flows differing significantly from linear predictions.

Comment on “Excitonic Recombination of Degenerate Two-Dimensional Electrons with Localized Photoexcited Holes in a Single Heterojunction Quantum Well”

1995 ◽  
Vol 74 (21) ◽  
pp. 4355-4355 ◽  
Author(s):  
P. O. Holtz ◽  
Q. X. Zhao ◽  
C. I. Harris ◽  
J. P. Bergman ◽  
T. Lundström ◽  
...  
Keyword(s):  
Quantum Well ◽  
Two Dimensional ◽  
Excitonic Recombination

EQUIVALENCE OF TWO-DIMENSIONAL GRAVITIES

1990 ◽  
Vol 05 (16) ◽  
pp. 1251-1258 ◽  
Author(s):  
NOUREDDINE MOHAMMEDI
Keyword(s):  
Gauge Theory ◽  
Explicit Solution ◽  
Light Cone ◽  
Equations Of Motion ◽  
Two Dimensional ◽  
Induced Gravity ◽  
Light Cone Gauge ◽  
Dimensional Gravity ◽  
The Relationship ◽  
Chern Simons

We find the relationship between the Jackiw-Teitelboim model of two-dimensional gravity and the SL (2, R) induced gravity. These are shown to be related to a two-dimensional gauge theory obtained by dimensionally reducing the Chern-Simons action of the 2+1 dimensional gravity. We present an explicit solution to the equations of motion of the auxiliary field of the Jackiw-Teitelboim model in the light-cone gauge. A renormalization of the cosmological constant is also given.

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