1,226 research outputs found
Stability of two-dimensional spatial solitons in nonlocal nonlinear media
We discuss existence and stability of two-dimensional solitons in media with
spatially nonlocal nonlinear response. We show that such systems, which include
thermal nonlinearity and dipolar Bose Einstein condensates, may support a
variety of stationary localized structures - including rotating spatial
solitons. We also demonstrate that the stability of these structures critically
depends on the spatial profile of the nonlocal response function.Comment: 8 pages, 9 figure
Stabilization of higher-order vortices and multi-hump solitons in media with synthetic nonlocal nonlinearities
We address the evolution of higher-order excited states, such as vortex and
multi-hump solitons, in nonlocal media with synthetic, competing focusing and
defocusing nonlinearities with different nonlocal transverse scales. We reveal
that introduction of suitable competing effects makes possible the
stabilization of vortex solitons with topological charge m>2, as well as
one-dimensional multi-hump solitons with number of humps p>4, all of which are
highly unstable in natural nonlocal materials with focusing nonlinearities.Comment: 14 pages, 5 figures, to appear in Physical Review
The frustrated Brownian motion of nonlocal solitary waves
We investigate the evolution of solitary waves in a nonlocal medium in the
presence of disorder. By using a perturbational approach, we show that an
increasing degree of nonlocality may largely hamper the Brownian motion of
self-trapped wave-packets. The result is valid for any kind of nonlocality and
in the presence of non-paraxial effects. Analytical predictions are compared
with numerical simulations based on stochastic partial differential equationComment: 4 pages, 3 figures
Nonlocal stabilization of nonlinear beams in a self-focusing atomic vapor
We show that ballistic transport of optically excited atoms in an atomic
vapor provides a nonlocal nonlinearity which stabilizes the propagation of
vortex beams and higher order modes in the presence of a self-focusing
nonlinearity. Numerical experiments demonstrate stable propagation of lowest
and higher order vortices over a hundred diffraction lengths, before
dissipation leads to decay of these structures.Comment: 3 figure
Complex light: Dynamic phase transitions of a light beam in a nonlinear non-local disordered medium
The dynamics of several light filaments (spatial optical solitons)
propagating in an optically nonlinear and non-local random medium is
investigated using the paradigms of the physics of complexity. Cluster
formation is interpreted as a dynamic phase transition. A connection with the
random matrices approach for explaining the vibrational spectra of an ensemble
of solitons is pointed out. General arguments based on a Brownian dynamics
model are validated by the numerical simulation of a stochastic partial
differential equation system. The results are also relevant for Bose condensed
gases and plasma physics.Comment: 11 pages, 20 figures. Small revisions, added a referenc
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