Oscillation frequencies as a function of the parameter <em>P</em> > 0 with <em>G</em> = −0.03, 0, 0.03 with lambda _{z}=sqrt{8}

2013-08-19T00:00:00Z (GMT) by Wei Qi Zhaoxin Liang Zhidong Zhang
<p><strong>Figure 8.</strong> Oscillation frequencies as a function of the parameter <em>P</em> > 0 with <em>G</em> = −0.03, 0, 0.03 with \lambda _{z}=\sqrt{8}. The labels on the curves refer to different oscillation modes (see text and figure <a href="http://iopscience.iop.org/0953-4075/46/17/175301/article#jpb468599f7" target="_blank">7</a>).</p> <p><strong>Abstract</strong></p> <p>We take into account the higher-order corrections in two-body scattering interactions within a mean-field description, and investigate the stability conditions and collective excitations of a harmonically trapped Bose–Einstein condensate (BEC). Our results show that the presence of higher-order corrections causes drastic changes to the stability condition of a BEC. In particular, we predict that with the help of the higher-order interaction, a BEC can now collapse even for positive scattering lengths; whereas, a usually unstable BEC with a negative scattering length can be stabilized by positive higher-order effects. The low-lying collective excitations are significantly modified as well, compared to those without the higher-order corrections. The conditions for a possible experimental scenario are also proposed.</p>