Unnamed: 0
int64
0
41k
title
stringlengths
4
274
category
stringlengths
5
18
summary
stringlengths
22
3.66k
theme
stringclasses
8 values
8,000
Asymmetric Squares as Standing Waves in Rayleigh-Benard Convection
nlin.PS
Possibility of asymmetric square convection is investigated numerically using a few mode Lorenz-like model for thermal convection in Boussinesq fluids confined between two stress free and conducting flat boundaries. For relatively large value of Rayleigh number, the stationary rolls become unstable and asymmetric squar...
physics
8,001
Application of the Entropy Production Principle to the Analysis of the Morphological Stability of a Growing Cylindrical Crystal
nlin.PS
Stability of cylindrical and spherical crystals growing from a supersaturated solution (in Mullins-Sekerka's approximation) is considered using the maximum entropy production principle. The concept of the binodal of the nonequilibrium (morphological) phase transition is introduced for interpretation of the obtained res...
physics
8,002
Multi-component optical solitary waves
nlin.PS
We discuss several novel types of multi-component (temporal and spatial) envelope solitary waves that appear in fiber and waveguide nonlinear optics. In particular, we describe multi-channel solitary waves in bit-parallel-wavelength fiber transmission systems for high performance computer networks, multi-colour paramet...
physics
8,003
Period Stabilization in the Busse-Heikes Model of the Kuppers-Lortz Instability
nlin.PS
The Busse-Heikes dynamical model is described in terms of relaxational and nonrelaxational dynamics. Within this dynamical picture a diverging alternating period is calculated in a reduced dynamics given by a time-dependent Hamiltonian with decreasing energy. A mean period is calculated which results from noise stabili...
physics
8,004
Patterns and localized structures in bistable semiconductor resonators
nlin.PS
We report experiments on spatial switching dynamics and steady state structures of passive nonlinear semiconductor resonators of large Fresnel number. Extended patterns and switching front dynamics are observed and investigated. Evidence of localization of structures is given.
physics
8,005
Spatial solitons in a semiconductor microresonator
nlin.PS
We show experimentally the existence of bright and dark spatial solitons in a passive quantum-well-semiconductor resonator of large Fresnel number. For the wavelength of observation the nonlinearity is mixed absorptive/defocusing. Bright solitons appear more stable than dark ones.
physics
8,006
Raman solitons in transient SRS
nlin.PS
We report the observation of Raman solitons on numerical simulations of transient stimulated Raman scattering (TSRS) with small group velocity dispersion. The theory proceeds with the inverse scattering transform (IST) for initial-boundary value problems and it is shown that the explicit theoretical solution obtained b...
physics
8,007
Three-dimensional pattern formation, multiple homogeneous soft modes, and nonlinear dielectric electroconvection
nlin.PS
Patterns forming spontaneously in extended, three-dimensional, dissipative systems are likely to excite several homogeneous soft modes ($\approx$ hydrodynamic modes) of the underlying physical system, much more than quasi one- and two-dimensional patterns are. The reason is the lack of damping boundaries. This paper co...
physics
8,008
Asymptotic Dynamics of Ripples
nlin.PS
A new nonlinear equation governing asymptotic dynamics of ripples is derived by using a short wave perturbative expansion on a generalized version of the Green-Naghdi system. It admits peakon solutions with amplitude, velocity and width in interrelation and static compacton solutions with amplitude and width in interre...
physics
8,009
Discreteness effects on soliton dynamics: a simple experiment
nlin.PS
We present a simple laboratory experiment to illustrate some aspects of the soliton theory in discrete lattices with a system that models the dynamics of dislocations in a crystal or the properties of adsorbed atomic layers. The apparatus not only shows the role of the Peierls-Nabarro potential but also illustrates the...
physics
8,010
Nonlinear Perturbation Theory
nlin.PS
An explicit perturbative solution to all orders is given for a general class of nonlinear differential equations. This solution is written as a sum indexed by rooted trees and uses the Green function of a linearization of the equations. The modifications due to the presence of zero-modes is considered. Possible diverge...
physics
8,011
Stability of Oscillating Hexagons in Rotating Convection
nlin.PS
Breaking the chiral symmetry, rotation induces a secondary Hopf bifurcation in weakly nonlinear hexagon patterns which gives rise to oscillating hexagons. We study the stability of the oscillating hexagons using three coupled Ginzburg-Landau equations. Close to the bifurcation point we derive reduced equations for the ...
physics
8,012
Front motion for phase transitions in systems with memory
nlin.PS
We consider the Allen-Cahn equations with memory (a partial integro-differential convolution equation). The prototype kernels are exponentially decreasing functions of time and they reduce the integrodifferential equation to a hyperbolic one, the damped Klein-Gordon equation. By means of a formal asymptotic analysis we...
physics
8,013
Two-frequency forced Faraday waves: Weakly damped modes and pattern selection
nlin.PS
Recent experiments (Kudrolli, Pier and Gollub, 1998) on two-frequency parametrically excited surface waves exhibit an intriguing "superlattice" wave pattern near a codimension-two bifurcation point where both subharmonic and harmonic waves onset simultaneously, but with different spatial wavenumbers. The superlattice p...
physics
8,014
Incoherent optical switching of semiconductor resonator solitons
nlin.PS
We demonstrate experimentally the bistable nature of the bright spatial solitons in a semiconductor microresonator and show that they can be created and destroyed by incoherent local optical injection.
physics
8,015
Dynamics of Lattice Kinks
nlin.PS
In this paper we consider two models of soliton dynamics (the sine Gordon and the \phi^4 equations) on a 1-dimensional lattice. We are interested in particular in the behavior of their kink-like solutions inside the Peierls- Nabarro barrier and its variation as a function of the discreteness parameter. We find explicit...
physics
8,016
Experimental generation of steering odd dark beams of finite length
nlin.PS
In this work we report the first realization of odd dark beams of finite length under controllable initial conditions. The mixed edge-screw phase dislocations are obtained by reproducing binary computer-generated holograms. Two effective ways to control the steering of the beams are analyzed experimentally and compared...
physics
8,017
Spatial Solitons in Resonators
nlin.PS
We describe experiments testing the existence and investigating the properties of spatial solitons in nonlinear resonators. We investigate the properties of stationary and moving spatial solitons in lasers with saturable absorber, with a subcritical bifurcation, as well as their manipulation. As opposed, spatial solito...
physics
8,018
A Quasicrystallic Domain Wall in Nonlinear Dissipative Patterns
nlin.PS
We propose an indirect approach to the generation of a two-dimensional quasiperiodic (QP) pattern in convection and similar nonlinear dissipative systems where a direct generation of stable uniform QP planforms is not possible. An {\it eightfold} QP pattern can be created as a broad transient layer between two domains ...
physics
8,019
Four-phase patterns in forced oscillatory systems
nlin.PS
We investigate pattern formation in self-oscillating systems forced by an external periodic perturbation. Experimental observations and numerical studies of reaction-diffusion systems and an analysis of an amplitude equation are presented. The oscillations in each of these systems entrain to rational multiples of the p...
physics
8,020
Phase Dynamics of Nearly Stationary Patterns in Activator-Inhibitor Systems
nlin.PS
The slow dynamics of nearly stationary patterns in a FitzHugh-Nagumo model are studied using a phase dynamics approach. A Cross-Newell phase equation describing slow and weak modulations of periodic stationary solutions is derived. The derivation applies to the bistable, excitable, and the Turing unstable regimes. In t...
physics
8,021
Nonlinear Stability of Bifurcating Front Solutions for the Taylor-Couette Problem
nlin.PS
We consider the Taylor-Couette problem in an infinitely extended cylindrical domain. There exist modulated front solutions which describe the spreading of the stable Taylor vortices into the region of the unstable Couette flow. These transient solutions have the form of a front-like envelope advancing in the laboratory...
physics
8,022
Non-linear Stability of Modulated Fronts for the Swift-Hohenberg Equation
nlin.PS
We consider front solutions of the Swift-Hohenberg equation $\partial_t u= -(1+\partial_x^2)^2 u +\epsilon ^2 u -u^3$. These are traveling waves which leave in their wake a periodic pattern in the laboratory frame. Using renormalization techniques and a decomposition into Bloch waves, we show the non-linear stability o...
physics
8,023
Spontaneous pattern formation in driven nonlinear lattice
nlin.PS
We demonstrate the spontaneous formation of spatial patterns in a damped, ac-driven cubic Klein-Gordon lattice. These patterns are composed of arrays of intrinsic localized modes characteristic for nonlinear lattices. We analyze the modulation instability leading to this spontaneous pattern formation. Our c...
physics
8,024
Higher-order nonlinear modes and bifurcation phenomena due to degenerate parametric four-wave mixing
nlin.PS
We demonstrate that weak parametric interaction of a fundamental beam with its third harmonic field in Kerr media gives rise to a rich variety of families of non-fundamental (multi-humped) solitary waves. Making a comprehensive comparison between bifurcation phenomena for these families in bulk media and planar wavegui...
physics
8,025
Oscillations and defect turbulence in a shallow fluidized bed
nlin.PS
We report an experimental study of the dynamics of an air-fluidized thin granular layer. Near-onset behavior of this shallow fluidized bed was described in the earlier paper (Tsimring et al, 1999). Above the threshold of fluidization the system exhibits a Hopf bifurcation as the layer starts to oscillate at a certain f...
physics
8,026
Characterization of the Emergence of Order in an Oscillated Granular Layer
nlin.PS
The formation of textured patterns has been predicted to occur in two stages. The first is an early time, domain-forming stage with dynamics characterized by a disorder function $\bar\delta (\beta) \sim t^{-\sigma_{E}}$, with $\sigma_{E} = {1/2}\beta$; this decay is universal. Coarsening of domains occurs in the second...
physics
8,027
Parametric localized modes in quadratic nonlinear photonic structures
nlin.PS
We analyze two-color spatially localized modes formed by parametrically coupled fundamental and second-harmonic fields excited at quadratic (or chi-2) nonlinear interfaces embedded into a linear layered structure --- a quasi-one-dimensional quadratic nonlinear photonic crystal. For a periodic lattice of nonlinear inter...
physics
8,028
Breather initial profiles in networks of weakly coupled anharmonic oscillators
nlin.PS
Qualitative information about breather initial profiles in the weak coupling limit of a chain of identical one-dimensional anharmonic oscillators is found by studying the linearized equations of motion at a one-site breather. In particular, information is found about how the breather initial profile depends on its peri...
physics
8,029
Drifting Pattern Domains in a Reaction-Diffusion System with Nonlocal Coupling
nlin.PS
Drifting pattern domains (DPDs), moving localized patches of traveling waves embedded in a stationary (Turing) pattern background and vice versa, are observed in simulations of a reaction-diffusion model with nonlocal coupling. Within this model, a region of bistability between Turing patterns and traveling waves arise...
physics
8,030
Nonlocal Boundary Dynamics of Traveling Spots in a Reaction-Diffusion System
nlin.PS
The boundary integral method is extended to derive closed integro-differential equations applicable to computation of the shape and propagation speed of a steadily moving spot and to the analysis of dynamic instabilities in the sharp boundary limit. Expansion of the boundary integral near the locus of traveling instabi...
physics
8,031
Nearest pattern interaction and global pattern formation
nlin.PS
We studied the effect of nearest pattern interaction on a globally pattern formation in a 2-dimensional space, where patterns are to grow initially from a noise in the presence of periodic supply of energy. Although our approach is general, we found that this study is relevant in particular to the pattern formation on ...
physics
8,032
Multistep cascading and fourth-harmonic generation
nlin.PS
We apply the concept of multistep cascading to the problem of fourth-harmonic generation in a single quadratic crystal. We analyze a new model of parametric wave mixing and describe its stationary solutions for two- and three-color plane waves and spatial solitons. Some applications to the optical frequency division as...
physics
8,033
"Embedded solitons": solitary waves in resonance with the linear spectrum
nlin.PS
It is commonly held that a necessary condition for the existence of solitons in nonlinear-wave systems is that the soliton's frequency (spatial or temporal) must not fall into the continuous spectrum of radiation modes. However, this is not always true. We present a new class of {\it % codimension-one} solitons (i.e., ...
physics
8,034
Spatial period-multiplying instabilities of hexagonal Faraday waves
nlin.PS
A recent Faraday wave experiment with two-frequency forcing reports two types of `superlattice' patterns that display periodic spatial structures having two separate scales [1]. These patterns both arise as secondary states once the primary hexagonal pattern becomes unstable. In one of these patterns (so-called `superl...
physics
8,035
Pattern formation with a conservation law
nlin.PS
Pattern formation in systems with a conserved quantity is considered by studying the appropriate amplitude equations. The conservation law leads to a large-scale neutral mode that must be included in the asymptotic analysis for pattern formation near onset. Near a stationary bifurcation, the usual Ginzburg--Landau equa...
physics
8,036
Nonsteady condensation and evaporation waves
nlin.PS
We study motion of a phase transition front at a constant temperature between stable and metastable states in fluids with the universal Van der Waals equation of state (which is valid sufficiently close to the fluid's critical point). We focus on a case of relatively large metastability and low viscosity, when it can b...
physics
8,037
Solitons in nonlocal nonlinear media: exact results
nlin.PS
We investigate the propagation of one-dimensional bright and dark spatial solitons in a nonlocal Kerr-like media, in which the nonlocality is of general form. We find an exact analytical solution to the nonlinear propagation equation in the case of weak nonlocality. We study the properties of these solitons and show th...
physics
8,038
Ring dark solitary waves: experiment versus theory
nlin.PS
Theoretical and experimental results on optical ring dark solitary waves are presented, emphasizing the interplay between initial dark beam contrast, phase-shift magnitude, background-beam intensity and saturation of the nonlinearity are presented. The results are found to confirm qualitatively the existing analytical ...
physics
8,039
Scattering of light by molecules of light
nlin.PS
We study the scattering properties of optical dipole-mode vector solitons recently predicted theoretically and generated in a laboratory. We demonstrate that such a radially asymmetric composite self-trapped state resembles ``a molecule of light'' which is extremely robust, survives a wide range of collisions, and disp...
physics
8,040
Spatiotemporally localized solitons in resonantly absorbing Bragg reflectors
nlin.PS
We predict the existence of spatiotemporal solitons (``light bullets'') in two-dimensional self-induced transparency media embedded in a Bragg grating. The "bullets" are found in an approximate analytical form, their stability being confirmed by direct simulations. These findings suggest new possibilities for signal tr...
physics
8,041
Directional coupling of optical signals by odd dark beams with mixed phase dislocations
nlin.PS
Numerical simulations on the evolution of step-screw and edge-screw optical phase dislocations in bulk saturable self-defocusing nonlinear media are presented, with emphasis on their ability to induce steering waveguides for signal beams (pulses). Two schemes for directional coupling of such signals, both ensuring reas...
physics
8,042
A simple model for the formation of vegetated dunes
nlin.PS
A simple model for the dynamics of dunes associated with vegetation is proposed. Using the model, formation processes of transverse dunes, parabolic dunes and elongated parabolic dunes according to two environmental factors: i)the amount of sand at the source, ii)the wind force, are simulated. The results have qualitat...
physics
8,043
Robustness of Quadratic Solitons with Periodic Gain
nlin.PS
We address the robustness of quadratic solitons with periodic non-conservative perturbations. We find the evolution equations for guiding-center solitons under conditions for second-harmonic generation in the presence of periodic multi-band loss and gain. Under proper conditions, a robust guiding-center soliton formati...
physics
8,044
Solitons in quadratic nonlinear photonic crystals
nlin.PS
We study solitons in one-dimensional quadratic nonlinear photonic crystals with modulation of both the linear and nonlinear susceptibilities. We derive averaged equations that include induced cubic nonlinearities and numerically find previously unknown soliton families. The inclusion of the induced cubic terms enables ...
physics
8,045
Stability of Spatial Optical Solitons
nlin.PS
We present a brief overview of the basic concepts of the soliton stability theory and discuss some characteristic examples of the instability-induced soliton dynamics, in application to spatial optical solitons described by the NLS-type nonlinear models and their generalizations. In particular, we demonstrate that the ...
physics
8,046
Observation of dipole-mode vector solitons
nlin.PS
We report on the first experimental observation of a novel type of optical vector soliton, a {\em dipole-mode soliton}, recently predicted theoretically. We show that these vector solitons can be generated in a photorefractive medium employing two different processes: a phase imprinting, and a symmetry-breaking instabi...
physics
8,047
On the boundary of the dispersion-managed soliton existence
nlin.PS
A breathing soliton-like structure in dispersion-managed (DM) optical fiber system is studied. It is proven that for negative average dispersion the breathing soliton is forbidden provided that a modulus of average dispersion exceed a threshold which depends on the soliton amplitude.
physics
8,048
Dispersion-managed soliton in optical fibers with zero average dispersion
nlin.PS
The dispersion-managed (DM) optical system with step-wise periodical variation of dispersion is studied in the framework of path-averaged Gabitov-Turitsyn equation. The soliton solution is obtained by iterating the path-averaged equation. The dependence of soliton parameters on dispersion map strength is investigated t...
physics
8,049
Resonantly Forced Inhomogeneous Reaction-Diffusion Systems
nlin.PS
The dynamics of spatiotemporal patterns in oscillatory reaction-diffusion systems subject to periodic forcing with a spatially random forcing amplitude field are investigated. Quenched disorder is studied using the resonantly forced complex Ginzburg-Landau equation in the 3:1 resonance regime. Front roughening and spon...
physics
8,050
Amplitude measurements of Faraday waves
nlin.PS
A light reflection technique is used to measure quantitatively the surface elevation of Faraday waves. The performed measurements cover a wide parameter range of driving frequencies and sample viscosities. In the capillary wave regime the bifurcation diagrams exhibit a frequency independent scaling proportional to the ...
physics
8,051
Derivation of Non-isotropic Phase Equations from a General Reaction-Diffusion Equation
nlin.PS
A non-isotropic version of phase equations such as the Burgers equation, the K-dV-Burgers equation, the Kuramoto-Sivashinsky equation and the Benney equation in the three-dimensional space is systematically derived from a general reaction-diffusion system by means of the renormalization group method.
physics
8,052
Nonlinearity and disorder: Classification and stability of nonlinear impurity modes
nlin.PS
We study the effects produced by competition of two physical mechanisms of energy localization in inhomogeneous nonlinear systems. As an example, we analyze spatially localized modes supported by a nonlinear impurity in the generalized nonlinear Schr\"odinger equation and describe three types of nonlinear impurity mode...
physics
8,053
Stable autosolitons in dispersive media with saturable gain and absorption
nlin.PS
We introduce the simplest one-dimensional model of a dispersive optical medium with saturable dissipative nonlinearity and filtering (dispersive loss) which gives rise to stable solitary pulses (autosolitons). In the particular case when the dispersive loss is absent, the same model may also be interpreted as describin...
physics
8,054
Breathing and randomly walking pulses in a semilinear Ginzburg-Landau system
nlin.PS
A system consisting of the cubic complex Ginzburg-Landau equation which is linearly coupled to an additional linear dissipative equation, is considered. The model was introduced earlier in the context of dual-core nonlinear optical fibers with one active and one passive cores. We argue that it may also possibly describ...
physics
8,055
Bragg-grating solitons in a semilinear dual-core system
nlin.PS
We investigate the existence and stability of gap solitons in a double-core optical fiber, where one core has the Kerr nonlinearity and the other one is linear, with the Bragg grating (BG) written on the nonlinear core, while the linear one may or may not have BG. The model considerably extends the previously studied f...
physics
8,056
Multi-soliton energy transport in anharmonic lattices
nlin.PS
We demonstrate the existence of dynamically stable multihump solitary waves in polaron-type models describing interaction of envelope and lattice excitations. In comparison with the earlier theory of multihump optical solitons [see Phys. Rev. Lett. {\bf 83}, 296 (1999)], our analysis reveals a novel physical mechanism ...
physics
8,057
Destabilization and Localization of Traveling Waves by an Advected Field
nlin.PS
{We study a model of small-amplitude traveling waves arising in a supercritical Hopf-bifurcation, that are coupled to a slowly varying, real field. The field is advected by the waves and, in turn, affects their stability via a coupling to the growth rate. In the absence of dispersion we identify two distinct shortwave ...
physics
8,058
Travelling solitons in the parametrically driven nonlinear Schroedinger equation
nlin.PS
We show that the parametrically driven nonlinear Schroedinger equation has wide classes of travelling soliton solutions, some of which are stable. For small driving strengths nonpropogating and moving solitons co-exist while strongly forced solitons can only be stably when moving sufficiently fast.
physics
8,059
Elliminating The Transverse Instabilities of Kerr Solitons
nlin.PS
We show analytically, numerically, and experimentally that a transversely stable one-dimensional [(1+1)D] bright Kerr soliton can exist in a 3D bulk medium. The transverse instability of the soliton is completely eliminated if it is made sufficiently incoherent along the transverse dimension. We derive a criterion for ...
physics
8,060
Escape angles in bulk chi(2) soliton interactions
nlin.PS
We develop a theory for non-planar interaction between two identical type I spatial solitons propagating at opposite, but arbitrary transverse angles in quadratic nonlinear (or so-called chi(2)) bulk media. We predict quantitatively the outwards escape angle, below which the solitons turn around and collide, and above ...
physics
8,061
Quasiperiodic Patterns in Boundary-Modulated Excitable Waves
nlin.PS
We investigate the impact of the domain shape on wave propagation in excitable media. Channelled domains with sinusoidal boundaries are considered. Trains of fronts generated periodically at an extreme of the channel are found to adopt a quasiperiodic spatial configuration stroboscopically frozen in time. The phenomeno...
physics
8,062
Propagation and interaction of ultrashort electromagnetic pulses in nonlinear media with a quadratic-cubic nonlinearity
nlin.PS
Propagation of extremely short unipolar pulses of electromagnetic field ("videopulses") is considered in the framework of a model in which the material medium is represented by anharmonic oscillators (approximating bound electrons) with quadratic and cubic nonlinearities. Two families of exact analytical solutions (wit...
physics
8,063
Light Bullet Modes in Self-Induced-Transparency Media with Refractive Index Modulation
nlin.PS
We predict the existence of a new type of spatiotemporal solitons ("light bullets") in two-dimensional self-induced-transparency media with refractive index modulation in the direction transverse to that of pulse propagation. These self-localized guided modes are found in an approximate analytical form, their existence...
physics
8,064
Spatiotemporal Patterns in Arrays of Coupled Nonlinear Oscillators
nlin.PS
Nonlinear reaction-diffusion systems admit a wide variety of spatiotemporal patterns or structures. In this lecture, we point out that there is certain advantage in studying discrete arrays, namely cellular neural/nonlinear networks (CNNs), over continuous systems. Then, to illustrate these ideas, the dynamics of diffu...
physics
8,065
Self-organized stable pacemakers near the onset of birhythmicity
nlin.PS
General amplitude equations for reaction-diffusion systems near to the soft onset of birhythmicity described by a supercritical pitchfork-Hopf bifurcation are derived. Using these equations and applying singular perturbation theory, we show that stable autonomous pacemakers represent a generic kind of spatiotemporal pa...
physics
8,066
A model for interacting instabilities and texture dynamics of patterns
nlin.PS
A simple model to study interacting instabilities and textures of resulting patterns for thermal convection is presented. The model consisting of twelve-mode dynamical system derived for periodic square lattice describes convective patterns in the form of stripes and patchwork quilt. The interaction between stationary ...
physics
8,067
Sideband Instabilities and Defects of Quasipatterns
nlin.PS
Quasipatterns have been found in dissipative systems ranging from Faraday waves in vertically vibrated fluid layers to nonlinear optics. We describe the dynamics of octagonal, decagonal and dodecagonal quasipatterns by means of coupled Ginzburg-Landau equations and study their stability to sideband perturbations analyt...
physics
8,068
Tunable front interaction and localization of periodically forced waves
nlin.PS
In systems that exhibit a bistability between nonlinear traveling waves and the basic state, pairs of fronts connecting these two states can form localized wave pulses whose stability depends on the interaction between the fronts. We investigate the localization of waves within the framework of coupled Ginzburg-Landau ...
physics
8,069
Propagation of Axi-Symmetric Nonlinear Shallow Water Waves over Slowly Varying Depth
nlin.PS
A problem in nonlinear water-wave propagation on the surface of an inviscid, stationary fluid is presented. The primary surface wave, suitably initiated at some radius, is taken to be a slowly evolving nonlinear cylindrical wave (governed by an appropriate Korteweg-de Vries equation); the depth is assumed to be varyi...
physics
8,070
Complexity at Mesoscale
nlin.PS
Through three examples we illustrate some of the concepts and ingredients required for pattern formation at mesoscopic scales. Two examples build on microscopic models where mesoscopic patterns emerge from homogeneous ground states driven into instability by external forcing. In contrast, the third example builds on a ...
physics
8,071
Model of the two level quantum dots ensemble interacting with coherent radiation
nlin.PS
We consider the model of quantum dots interacting with coherent radiation when the relaxation processes may be neglected. The system under investigation consists of two discrete energy levels of the quantum dots in the presence of strong electron-electron Coulomb interaction and the transitions between these levels in ...
physics
8,072
Propagation and interaction of extremely short electromagnetic pulses in non-linear media
nlin.PS
Propagation of the extremely short electromagnetic pulse in non-linear dielectric media without the slowly varying envelope approximation is discussed. The models under consideration take into account both resonant and not-resonant excitations of non-linear medium, and polarisation states of electromagnetic wave. Stead...
physics
8,073
Frequency Locking in Spatially Extended Systems
nlin.PS
A variant of the complex Ginzburg-Landau equation is used to investigate the frequency locking phenomena in spatially extended systems. With appropriate parameter values, a variety of frequency-locked patterns including flats, $\pi$ fronts, labyrinths and $2\pi/3$ fronts emerge. We show that in spatially extended syste...
physics
8,074
Confinement and death of oscillations in coupled chaotic bistable oscillators
nlin.PS
In coupled chaotic bistable systems such as Lorenz and Chua oscillators, two-phase domains corresponding to the two lobes of the strange attractor are formed. The dynamics of each domain is confined to one lobe and typically exhibits one of the two types of behavior: oscillation death or nearly periodic oscillations. W...
physics
8,075
Square to stripe transition and superlattice patterns in vertically oscillated granular layers
nlin.PS
We investigated the physical mechanism for the pattern transition from square lattice to stripes, which appears in vertically oscillating granular layers. We present a continuum model to show that the transition depends on the competition between inertial force and local saturation of transport. By introducing multiple...
physics
8,076
Minimal speed of fronts of reaction-convection-diffusion equations
nlin.PS
We study the minimal speed of propagating fronts of convection reaction diffusion equations of the form $u_t + \mu \phi(u) u_x = u_{xx} +f(u)$ for positive reaction terms with $f'(0 >0$. The function $\phi(u)$ is continuous and vanishes at $u=0$. A variational principle for the minimal speed of the waves is constructed...
physics
8,077
Pattern Formation Near Onset of a Convecting Fluid In an Annulus
nlin.PS
Numerical simulations of the time-dependent Swift-Hohenberg equation are used to test predictions of Cross [Phys. Rev. A 25:1065-1076 (1982)] that Rayleigh-Benard convection in the form of straight rolls or of an array of dislocations may be observed in an annular domain depending on the values of inner radius r_1, out...
physics
8,078
Accurate switching intensities and length scales in quasi-phase-matched materials
nlin.PS
We consider unseeded Type I second-harmonic generation in quasi-phase-matched (QPM) quadratic nonlinear materials and derive an accurate analytical expression for the evolution of the average intensity. The intensity-dependent nonlinear phase mismatch due to the QPM induced cubic nonlinearity is found. The equivalent f...
physics
8,079
Pattern and wavenumber selection in ferrofluids
nlin.PS
The formation of patterns of peaks on the free surface of a ferrofluid subject to a magnetic field normal to the undisturbed interface is investigated theoretically. The relative stability of ridge, square, and hexagon planforms is studied using a perturbative energy minimization procedure. Extending previous studies t...
physics
8,080
Resonance Effects in Topological Discrete sine-Gordon System
nlin.PS
We consider kink-antikink collisions in the topological discrete sine-Gordon system. We find that the TDSG kink supports extra internal modes of vibration and this results in resonance effects of the kind seen for the continuum phi^4 theory.
physics
8,081
Modulational instability in nonlocal nonlinear Kerr media
nlin.PS
We study modulational instability (MI) of plane waves in nonlocal nonlinear Kerr media. For a focusing nonlinearity we show that, although the nonlocality tends to suppress MI, it can never remove it completely, irrespectively of the particular profile of the nonlocal response function. For a defocusing nonlinearity th...
physics
8,082
One- and two-dimensional solitons in saturable media
nlin.PS
Very narrow spatial bright solitons in (1+1)D and (2+1)D versions of cubic-quintic and full saturable models are studied, starting from the full system of the Maxwell's equations, rather than from the paraxial (NLS) approximation. For the solitons with both TE and TM polarizations, it is shown that there always exists ...
physics
8,083
Quadratic solitons in cubic crystals
nlin.PS
Starting from the Maxwell's equations and without resort to the paraxial approximation, we derive equations describing stationary (1+1)-dimensional beams propagating at an arbitrary direction in an optical crystal with cubic symmetry and purely quadratic nonlinearity. The equations are derived separately for beams with...
physics
8,084
Dispersion-managed soliton in a strong dispersion map limit
nlin.PS
A dispersion-managed optical system with step-wise periodical variation of dispersion is studied in a strong dispersion map limit in the framework of path-averaged Gabitov-Turitsyn equation. The soliton solution is obtained by iterating the path-averaged equation analytically and numerically. An efficient numerical alg...
physics
8,085
Stability of narrow beams in bulk Kerr-type nonlinear media
nlin.PS
We consider (2+1)-dimensional beams, whose transverse size may be comparable to or smaller than the carrier wavelength, on the basis of an extended version of the nonlinear Schr\"{o}dinger equation derived from the Maxwell`s equations. As this equation is very cumbersome, we also study, in parallel to it, its simplifie...
physics
8,086
Wavy stripes and squares in zero P number convection
nlin.PS
A simple model to explain numerically observed behaviour of chaotically varying stripes and square patterns in zero Prandtl number convection in Boussinesq fluid is presented. The nonlinear interaction of mutually perpendicular sets of wavy rolls, via higher mode, may lead to a competition between the two sets of wavy ...
physics
8,087
Zig-zag instability of an Ising wall in liquid crystals
nlin.PS
We present a theoretical explanation for the interfacial zigzag instability that appears in anisotropic systems. Such an instability has been experimentally highlighted for an Ising wall formed in a nematic liquid crystal cell under homeotropic anchoring conditions. From an envelope equation, relevant close to the Free...
physics
8,088
Drifting Abnormal Rolls in Electroconvection of Hybrid Aligned Nematic
nlin.PS
We report experimental and theoretical results on the conductive regime of electroconvection in hybrid aligned nematics. The drifting oblique/normal rolls below/above the Lifshitz frequency are observed at the onset of electroconvection under a.c. voltage. The experimental data on the threshold voltage, wavelength, obl...
physics
8,089
Crossover Between Flexoelectric Stripe Patterns and Electroconvection in Hybrid Aligned Nematics
nlin.PS
We report experimental and theoretical results on the flexoelectric instability and crossover between flexoelectric domains and electroconvection in a hybrid aligned nematic MBBA under d.c. voltage. At threshold a spatially periodic flexoelectric deformation in the form of longitudinal domains (along the planar directo...
physics
8,090
Observation of progressive motion of ac-driven solitons
nlin.PS
We report the first experimental observation of phase-locked motion of a topological soliton at a nonzero average velocity in a periodically modulated lossy medium, under the action of an ac force with no dc component [the effect was predicted by G. Filatrella, B.A. Malomed, and R.D. Parmentier, Phys. Lett. A 198, 43 (...
physics
8,091
Transition from oscillatory to excitable regime in a system forced at three times its natural frequency
nlin.PS
The effect of a temporal modulation at three times the critical frequency on a Hopf bifurcation is studied in the framework of amplitude equations. We consider a complex Ginzburg-Landau equation with an extra quadratic term, resulting from the strong coupling between the external field and the unstable modes. We show t...
physics
8,092
Statistical Theory for Incoherent Light Propagation in Nonlinear Media
nlin.PS
A novel statistical approach based on the Wigner transform is proposed for the description of partially incoherent optical wave dynamics in nonlinear media. An evolution equation for the Wigner transform is derived from a nonlinear Schrodinger equation with arbitrary nonlinearity. It is shown that random phase fluctuat...
physics
8,093
New connections between moving curves and soliton equations
nlin.PS
Lamb has identified a certain class of moving space curves with soliton equations. We show that there are two other classes of curve evolution that may be so identified. Hence three distinct classes of curve evolution are associated with a given integrable equation. The nonlinear Schr\"{o}dinger equation is used to ill...
physics
8,094
Semiconductor resonator solitons above band gap
nlin.PS
We show experimentally the existence of bright and dark spatial solitons in semiconductor resonators for excitation above the band gap energy. These solitons can be switched on, both spontaneously and with address pulses, without the thermal delay found for solitons below the band gap which is unfavorable for applicati...
physics
8,095
Spatial solitons in a pumped semiconductor resonator
nlin.PS
Bright and dark spatial solitons are observed in an optically pumped semiconductor resonator. The pumping allows to considerably reduce the light intensity necessary for the existence of the solitons and alleviates thermal load problems. Experiments are found to agree with calculations based on a simple large aperture ...
physics
8,096
Ramped-induced states in a parametrically driven Ginzburg-Landau equation
nlin.PS
We introduce a parametrically driven Ginzburg-Landau (GL) model, which admits a gradient representation, and is subcritical in the absence of the parametric drive (PD). In the case when PD acts uniformly in space, this model has a stable kink solution. A nontrivial situation takes places when PD is itself subject to a ...
physics
8,097
Families of Bragg-grating solitons in a cubic-quintic medium
nlin.PS
We investigate the existence and stability of solitons in an optical waveguide equipped with a Bragg grating (BG) in which nonlinearity contains both cubic and quintic terms. The model has straightforward realizations in both temporal and spatial domains, the latter being most realistic. Two different families of zero-...
physics
8,098
Generic features of modulational instability in nonlocal Kerr media
nlin.PS
The modulational instability (MI) of plane waves in nonlocal Kerr media is studied for a general, localized, response function. It is shown that there always exists a finite number of well-separated MI gain bands, with each of them characterised by a unique maximal growth rate. This is a general property and is demonst...
physics
8,099
Generalized Optimal Velocity Model for Traffic Flow
nlin.PS
A generalized optimal velocity model is analyzed, where the optimal velocity function depends not only on the headway of each car but also the headway of the immediately preceding one. The stability condition of the model is derived by considering a small perturbation around the homogeneous flow solution. The effect of...
physics