We discuss the formation of bright solitons in a Bose-Einstein
condensate (BEC) of 7Li atoms induced by a sudden change in the sign
of the scattering length from positive to negative,
as reported in a recent experiment .
The numerical simulations are performed by
using the Gross-Pitaevskii equation (GPE) with a
dissipative three-body term. We show that a number of
bright solitons is produced and this can be interpreted
in terms of the modulational instability of the
time-dependent macroscopic wave function of the BEC.
In particular, we derive a simple formula for the number
of solitons that is in good agreement with the numerical results.
By investigating the long time evolution of the soliton train
we find that adjacent solitons repel each other
due to their phase difference.
In addition, we find that during the motion of
the soliton train in an axial harmonic potential the number of
solitonic peaks changes in time and the density of individual peaks
shows an intermittent behavior .
K.E. Strecker et al., Nature 417, 150 (2002). L. Salasnich, A. Parola, and L. Reatto, Phys. Rev. Lett. 91, 080405 (2003).
Seminarsko predavanje bo v petek 24. oktobra 2003 ob 15:15 uri v seminarski sobi CAMTP, Krekova 2, pritlicje. Vljudno vabljeni vsi zainteresirani, tudi študenti.