Speaker
Dr
Magnus Johansson
(Linköping University)
Description
Considering a two-dimensional lattice of weakly coupled
waveguides,where each waveguide may carry two orthogonal
modes of dipolar character, we present a nonlinear discrete
vector model for the study of Kerr optical solitons with
profiles having a reduced symmetry relative to the
underlying lattice. We describe analytically and numerically
existence and stability properties of such states in square
and triangular lattices and also reveal directional mobility
properties of two-dimensional gap solitons which were
recently observed in experiment. The model also describes
one-site peaked discrete vortices corresponding to
experimentally observed second-band vortex lattice solitons,
for which oscillatory instabilities are predicted. We also
introduce a concept of rotational Peierls-Nabarro barrier
characterizing the minimum energy needed for rotation of
stable dipole modes and compare numerically translational
and rotational energy barriers in regimes of good mobility.
A similar model has also recently been proposed as a
mean-field model for p-band bosons in optical lattices,
describing quantum states in the superfluid regime.
Primary author
Dr
Magnus Johansson
(Linköping University)
