Excitation of gap discrete breathers in an A3B crystal with a flux of particles

Abstract

The generation of discrete breathers in an A3B crystal has been modeled by the method of molecular dynamics using Pt3Al as an example via the application of random unidirectional momenta, which simulate the action of a particle flux, to atoms. Two possible mechanisms of the excitation of gap discrete breathers with a soft type of nonlinearity have been revealed depending on the energy of particles in a flux. If a particle is able to transfer energy of more than 1.4 eV to the Al atom, a discrete breather can be excited by the only particle. Otherwise, a discrete breather is formed upon numerous particle–Al atom collisions, which are possible only at a sufficiently high density of particles, as each following particle must transfer its momentum to the Al atom before its oscillations provoked by previous particles attenuate.