Stability of Bose-Einstein condensates

David C K Roberts, Masahito Ueda

We derive the dynamic and thermodynamic stability conditions for dilute multicomponent Bose-Einstein condensates (BECs). These stability conditions, generalized for $n$-component BECs, are found to be equivalent and are shown to be consistent with the phase diagrams of two- and three-component condensates that are derived from energetic arguments.

Jian Zhang

Sadhan K. Adhikari

Barnali Chakrabarti, Tapan Kumar Das, Pankaj Kumar Debnath

We study the stability of Bose-Einstein condensate (BEC) with repulsive and attractive interatomic interactions in a harmonic plus quartic trap $[V(r)=\frac{1}{2}m{\ensuremath{\omega}}^{2}{r}^{2}+\ensuremath{\lambda}{r}^{4}]$. We find that BEC with repulsive interaction becomes more stable for $\ensuremath{\lambda}>0$. For $\ensuremath{\lambda}<0$, we observe a different metastability of the condensate even when the scattering length is positive. For BEC with attractive interaction, we observe dramatic change in the stability factor $\frac{{A}_{\text{cr}}|{a}_{\text{sc}}|}{{a}_{\text{ho}}}$ due to the anharmonicity. The frequencies of the collective excitations are also modified by the atomic interaction and by the anharmonicity.

Muhammad Irfan Qadir, Aleen Ijaz

We consider a system of effectively one dimensional cigar shaped Bose Einstein condensate. We present a numerical study for the existence and stability of travelling bright solitons in the time dependent nonlinear Schrodinger equation that describes the dynamics of Bose-Einstein ¨ condensate. Furthermore, the effects of strength of the trap on the stability of bright solitons are investigated when the condensate is placed under the influence of a trapping potential.

Joseph V. Pulé