Equilibrium widths <em>v<sub>z</sub></em> (a) and <em>v</em> (b) come from equations (15) and (15) as a function of |<em>P</em>| for <em>G</em> = 0.03, 0 and −0.03 respectively in the case of cylindrical symmetry of λ<sub><em>z</em></sub> = 2

2013-08-19T00:00:00Z (GMT) by Wei Qi Zhaoxin Liang Zhidong Zhang
<p><strong>Figure 10.</strong> Equilibrium widths <em>v<sub>z</sub></em> (a) and <em>v</em> (b) come from equations (<a href="http://iopscience.iop.org/0953-4075/46/17/175301/article#jpb468599eqn18" target="_blank">15</a>) and (<a href="http://iopscience.iop.org/0953-4075/46/17/175301/article#jpb468599eqn19" target="_blank">15</a>) as a function of |<em>P</em>| for <em>G</em> = 0.03, 0 and −0.03 respectively in the case of cylindrical symmetry of λ<sub><em>z</em></sub> = 2.</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>