Supersonic voidions in 2D Morse lattice
E.A. Korznikova, Institute of Molecule and Crystal Physics, Ufa Federal Research Centre of Russian Academy of Sciences, Ufa, Russia; I.A. Shepelev, Saratov State University, Russia; D.S. Ryabov, Southern Federal University, Institute of Physics, Rostov-on-Don, Russia; S.V. Dmitriev, Institute of Molecule and Crystal Physics, Ufa Federal Research Centre of Russian Academy of Sciences, Ufa, Russia
Abstract
Dynamics of M-crowdion clusters (M=1, 2 or 3) and vacancy clusters is analyzed in 2D triangular lattice with Morse interactions. Topological defects are created in the lattice by kicking three neighboring atoms in the three neighboring close-packed atomic rows along the rows. Initial velocity of the atoms in the inner row v_inn, can be positive or negative, while the velocities of both atoms in the outer rows v_out, are equal and positive. The case of v_inn=v_out was analyzed earlier and it was found that if the initial velocity is sufficiently large then a 3-crowdion cluster and a three-vacancy are formed. Two major effects are reported in the case of v_inn ≠ v_out analyzed here. (i) Due to the difference in the initial velocities, topological defects can be produced in the lattice with smaller initial energy than in the case of v_inn =v_out. (ii) In certain range of the initial velocities, a vacancy can appear at a distance of dozens interatomic distances from the initiation point, moving along the close-packed row with supersonic speed. Such moving vacancy is called voidion and mechanism of its formation and motion is revealed. Our results uncover new mechanisms of mass transfer by solitary waves in nonlinear lattices.
Speaker
Korznikova Elena A.
Institute of Molecule and Crystal Physics, Ufa Federal Research Centre of Russian Academy of Sciences, Oktyabrya Ave. 151, Ufa 450075, Russia
Russia
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