4 research outputs found
Laser tweezers for atomic solitons
We describe a controllable and precise laser tweezers for Bose-Einstein
condensates of ultracold atomic gases. In our configuration, a laser beam is
used to locally modify the sign of the scattering length in the vicinity of a
trapped BEC. The induced attractive interactions between atoms allow to extract
and transport a controllable number of atoms. We analyze, through numerical
simulations, the number of emitted atoms as a function of the width and
intensity of the outcoupling beam. We also study different configurations of
our system, as the use of moving beams. The main advantage of using the control
laser beam to modify the nonlinear interactions in comparison to the usual way
of inducing optical forces, i.e. through linear trapping potentials, is to
improve the controllability of the outcoupled solitary wave-packet, which opens
new possibilities for engineering macroscopic quantum states.Comment: 6 pages, 7 figure
Solitary waves for linearly coupled nonlinear Schrodinger equations with inhomogeneous coefficients
Motivated by the study of matter waves in Bose-Einstein condensates and
coupled nonlinear optical systems, we study a system of two coupled nonlinear
Schrodinger equations with inhomogeneous parameters, including a linear
coupling. For that system we prove the existence of two different kinds of
homoclinic solutions to the origin describing solitary waves of physical
relevance. We use a Krasnoselskii fixed point theorem together with a suitable
compactness criterion.Comment: 16 page