Search results for " Simulation"

Dark-and-bright rogue waves in long wave-short wave resonance

2014

Nonlinear Photonics, Bragg Gratings, Photosensitivity, and Poling in Glass Waveguides, in Proceedings Advanced Photonics, Part of Advanced Photonics, Barcelona, Spain, 28-31 July 2014

Quantum coherence and fast-gain effects in laser modelocking: The coherent master equation

2021

Modelocking embraces a variety of techniques leading to the periodic emission of ultrashort laser pulses, typically on the picosecond scale and below, whose impact in science and technology can be hardly exaggerated.

2018

In this manuscript, we experimentally and numerically investigate the chaotic dynamics of the state-of-polarization in a nonlinear optical fiber due to the cross-interaction between an incident signal and its intense backward replica generated at the fiber-end through an amplified reflective delayed loop. Thanks to the cross-polarization interaction between the two-delayed counter-propagating waves, the output polarization exhibits fast temporal chaotic dynamics, which enable a powerful scrambling process with moving speeds up to 600-krad/s. The performance of this all-optical scrambler was then evaluated on a 10-Gbit/s On/Off Keying telecom signal achieving an error-free transmission. We a…

Crack dynamics and crack surfaces in elastic beam lattices

1998

The dynamics of propagating cracks is analyzed in elastic two-dimensional lattices of beams. At early times, inertia effects and static stress enhancement combine so that the crack-tip velocity is found to behave as t1/7. At late times a minimal crack-tip model reproduces the numerical simulation results. With no disorder and for fast loading, a “mirror-mist-mirror” crack-surface pattern emerges. Introduction of disorder leads, however, to the formation of the “mirror-mist-hackle”–type interface typical in many experimental situations. Peer reviewed

Lattice Boltzmann versus Molecular Dynamics simulations of nanoscale hydrodynamic flows

2006

A fluid flow in a simple dense liquid, passing an obstacle in a two-dimensional thin film geometry, is simulated by Molecular Dynamics (MD) computer simulation and compared to results of Lattice Boltzmann (LB) simulations. By the appropriate mapping of length and time units from LB to MD, the velocity field as obtained from MD is quantitatively reproduced by LB. The implications of this finding for prospective LB-MD multiscale applications are discussed.

Plenty of motion at the bottom: atomically thin liquid gold membrane

2015

The discovery of graphene some ten years ago was the first proof of a free-standing two-dimensional (2D) solid phase. Here, using quantum molecular dynamics simulations of nanoscale gold patches suspended in graphene pores, we predict the existence of an atomically thin, free-standing 2D liquid phase. The liquid phase, enabled by the exceptional planar stability of gold due to relativistic effects, demonstrates extreme fluxionality of metal nanostructures and opens possibilities for a variety of nanoscale phenomena.

A Monte Carlo Study of the Low-Temperature Properties of Strongly Correlated Localized Particles in Disordered Systems

1993

A computer simulation method is presented, which yields the ground state as well as the low-energy excitations for disordered systems of many interacting particles. The efficiency of the method is demonstrated by the application to the Coulomb glass, i.e. many localized electrons with long-range interaction. The obtained knowledge about the specific configurations of a large number of excited states is only the starting point for further investigations. First results are presented which shed a new light on old controversies about the behaviour of correlated electrons within the Coulomb gap regime.

Anomalous thermalization of nonlinear optical waves

2010

We report theoretically and experimentally an anomalous thermalization process characterized by an irreversible evolution of the waves towards a novel family of equilibrium states of a fundamental different nature than the standard thermodynamic equilibrium state.

Finite-size scaling analysis of the anisotropic critical behavior of the two-dimensional Ising model under shear

2010

The critical behavior of the two-dimensional Ising Model with non-conserved order parameter in steady-state shear is studied by large-scale Monte Carlo simulations. Studying the structure factor S(qx,qy) in the disordered phase, the ratio of correlation length exponents νx/νy in the two lattice directions (x,y) is estimated, and the critical temperature is determined as a function of the shear rate as Tc() − Tc(0) ∝ with ≈0.45. Critical exponents β≈0.37, γ≈1.1, ; ν⊥≈0.46, ν∥≈1.38 are roughly compatible with anisotropic hyperscaling.

ON FRACTIONAL RELAXATION

2003

Generalized fractional relaxation equations based on generalized Riemann-Liouville derivatives are combined with a simple short time regularization and solved exactly. The solution involves generalized Mittag-Leffler functions. The associated frequency dependent susceptibilities are related to symmetrically broadened Cole-Cole susceptibilities occurring as Johari Goldstein β-relaxation in many glass formers. The generalized susceptibilities exhibit a high frequency wing and strong minimum enhancement.