1 research outputs found
Nonstationary excitations in Bose-Einstein condensates under the action of periodically varying scattering length with time dependent frequencies
We investigate nonstationary excitations in 3D-Bose-Einstein condensates in a
spherically symmetric trap potential under the modulation of scattering length
with slowly varying frequencies (adiabatic modulation). By numerically solving
the Gross-Pitaevskii equation we observe a step-wise increase in the amplitude
of oscillation due to successive phase locking between driving frequency and
nonlinear frequency. Such a nonstationary excitation has been shown to exist by
an analytic approach using variational procedure and perturbation theory in the
action-angle variables. By using a canonical perturbation theory, we have
identified the successive resonance excitations whenever the driven frequency
matches the nonlinear frequency or its subharmonics.Comment: 17 pages, 6 figures (to be published in Physica D