1201.5758 (Luiza Angheluta et al.)

Anisotropic velocity statistics of topological defects under shear flow    [PDF]

Luiza Angheluta, Patricio Jeraldo, Nigel Goldenfeld

We report numerical results on the velocity statistics of topological defects
during the dynamics of phase ordering and non-relaxational evolution assisted
by an external shear ow. We propose a numerically efficient tracking method for
finding the position and velocity of defects, and apply it to vortices in a
uniform field and dislocations in anisotropic stripe patterns. During
relaxational dynamics, the distribution function of the velocity fuctuations is
characterized by a dynamical scaling with a scaling function that has a robust
algebraic tail with an inverse cube power law. This is characteristic to
defects of codimension two, e.g. point defects in two dimensions and filaments
in three dimensions, regardless of whether the motion is isotropic (as for
vortices) or highly anisotropic (as for dislocations). However, the anisotropic
dislocation motion leads to anisotropic statistical properties when the
interaction between defects and their motion is in infuenced by the presence of
an external shear flow transverse to the stripe orientation.

View original: http://arxiv.org/abs/1201.5758