Interaction of moving discrete breathers with vacancies
نویسنده
چکیده
In this paper a Frenkel–Kontorova model with a nonlinear interaction potential is used to describe a vacancy defect in a crystal. According to recent numerical results [Cuevas et al. Phys. Lett. A 315, 364 (2003)] the vacancy can migrate when it interacts with a moving breather. We study more thoroughly the phenomenology caused by the interaction of moving breathers with a single vacancy and also with double vacancies. We show that vacancy mobility is strongly correlated with the existence and stability properties of stationary breathers centered at the particles adjacent to the vacancy, which we will now call vacancy breathers.
منابع مشابه
Interaction of Moving Breathers with an Impurity
We analyze the influence of an impurity in the evolution of moving discrete breathers in a Klein–Gordon chain with non-weak nonlinearity. Three different behaviours can be observed when moving breathers interact with the impurity: they pass through the impurity continuing their direction of movement; they are reflected by the impurity; they are trapped by the impurity, giving rise to chaotic br...
متن کاملEffective Hamiltonian for travelling discrete breathers
Hamiltonian chains of oscillators in general probably do not sustain exact travelling discrete breathers. However solutions which look like moving discrete breathers for some time are not difficult to observe in numerics. In this paper we propose an abstract framework for the description of approximate travelling discrete breathers in Hamiltonian chains of oscillators. The method is based on th...
متن کامل1 5 O ct 1 99 7 Moving discrete breathers ?
We give definitions for different types of moving spatially localized objects in discrete nonlinear lattices. We derive general analytical relations connecting frequency, velocity and localization length of moving discrete breathers and kinks in nonlinear one-dimensional lattices. Then we propose numerical algorithms to find these solutions.
متن کاملEffective Hamiltonian for Traveling Discrete Breathers in the Fpu Chain
For the Fermi-Pasta-Ulam chain, an effective Hamiltonian is constructed, describing the motion of approximate, weakly localized discrete breathers traveling along the chain. The velocity of these moving and localized vibrations can be estimated analytically as the group velocity of the corresponding wave packet. The Peierls-Nabarro barrier is estimated for strongly localized discrete breathers.
متن کاملComputational Studies of Discrete Breathers - from Basics to Competing Length Scales
This work provides a description of the main computational tools for the study of discrete breathers. It starts with the observation of breathers through simple numerical runs, the study uses targeted initial conditions, and discrete breather impact on transient processes and thermal equilibrium. We briefly describe a set of numerical methods to obtain breathers up to machine precision. In the ...
متن کامل