Interaction of propagating discrete breathers with a vacancy in a two-dimensional crystal

The interaction of discrete breathers (DBs) propagating along a close-packed atomic row with a vacancy situated in the same row has been studied by molecular dynamics in a two-dimensional monoatomic crystal with the Morse interatomic potential. It is established that DBs moving at a velocity below a certain threshold exhibit elastic repulsion from the vacancy, while DBs with velocities above this threshold are scattered on the vacancy. The interaction of DBs with a vacancy decreases the energy barrier for vacancy migration in the crystal.