Evolution of the condensate width v in a spherically symmetric trap
Figure 3. Evolution of the condensate width v in a spherically symmetric trap. Parameters are as follows: (a) G = 0, (b) G = −0.03 and (c) G = 0.03 with P = 0.613 and v(0) = 4.332.
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.