Related papers: Condition for the Existence of Complex Modes in a …
Mode-mixing of coherent excitations of a trapped Bose-Einstein condensate is modelled using the Bogoliubov approximation. Hybridization of the modes of the breather ($l=0$) and surface ($l=4$) states leads to the formation of a Bogoliubov…
The collective modes of a rotating Bose-Einstein condensate confined in an attractive quadratic plus quartic trap are investigated. Assuming the presence of a large number of vortices we apply the diffused vorticity approach to the system.…
Recent experiments have employed rapidly expanding toroidal Bose-Einstein condensates (BECs) to mimic the inflationary expansion in the early universe. One expected signature of the expansion in such experiments is spontaneous particle…
The occurrence of phase fluctuations due to thermal excitations in Bose-Einstein condensates (BECs) is studied for a variety of temperatures and trap geometries. We observe the statistical nature of the appearence of phase fluctuations and…
We analyze, analytically and numerically, the position, momentum, and in particular the angular-momentum variance of a Bose-Einstein condensate (BEC) trapped in a two-dimensional anisotropic trap for static and dynamic scenarios. The…
We consider the fluctuations in atom number that occur within finite-sized measurement cells in a trapped Bose-Einstein condensate (BEC). This approximates the fluctuation measurements made in current experiments with finite resolution in…
We apply the concepts of nonlinear guided-wave optics to a Bose-Einstein condensate (BEC) trapped in an external potential. As an example, we consider a parabolic double-well potential and derive coupled-mode equations for the complex…
We study analytically and asymptotically as well as numerically ground states and dynamics of two-component spin-orbit-coupled Bose-Einstein condensates (BECs) modeled by the coupled Gross-Pitaevskii equations (CGPEs). In fact, due to the…
We investigate the phase structure of two-component Bose-Einstein condensates (BECs) with repulsive intra- and interspecies interactions in the presence of respective vortex-antivortex superposition states (VAVSS). We show that different…
The response of a trapped Bose-Einstein condensed gas to a periodic driving force is studied theoretically in the framework of the nonlinear Gross-Pitaevskii equation. The monopole mode is driven by periodical modulation of the frequency of…
We suggest a method to create turbulence in a trapped atomic Bose-Einstein condensate (BEC). By replacing in the upper half part of our box the wave function, Psi, with its complex conjugate, Psi^{*}, new negative vortices are introduced…
A Langevin equation for the complex amplitude of a single-mode Bose-Einstein condensate is derived. The equation is first formulated phenomenologically, defining three transport parameters. It is then also derived microscopically.…
An optical speckle potential is used to investigate the static and dynamic properties of a Bose-Einstein condensate in the presence of disorder. For strong disorder the condensate is localized in the deep wells of the potential. With…
We study the dynamics of three-dimensional weakly linked Bose-Einstein condensates using a multimode model with an effective interaction parameter. The system is confined by a ring-shaped four-well trapping potential. By constructing a…
Multiply quantized vortices in trapped Bose-Einstein condensates are studied using the Bogoliubov theory. Suitable combinations of a localized pinning potential and external rotation of the system are found to energetically stabilize, both…
The stability of doubly quantized vortices in dilute Bose-Einstein condensates of 23Na is examined at zero temperature. The eigenmode spectrum of the Bogoliubov equations for a harmonically trapped cigar-shaped condensate is computed and it…
We study fundamental and vortical solitons in disk-morphed Bose-Einstein condensates (BECs) subject to strong confinement along the axial direction. Starting from the three-dimensional (3D) Gross-Pitaevskii equation (GPE), we proceed to an…
With phase space analysis approach, we investigate thoroughly the self-trapping phenomenon for two weakly coupled Bose-Einstein condensates (BEC) in a symmetric double-well potential. We identify two kinds of self-trapping by their…
We study the stability and dynamics of vortices in two-species condensates using a two mode model. The recent experimental results obtained at JILA (M. R. Matthews, {\em et al.}, Phys. Rev. Lett. 83 (1999) 2498) and theoretical predictions…
We numerically examine the corotation of two parallel quantized vortices in a self-gravitating Bose-Einstein condensate (BEC) employing the Gross-Pitaevskii-Poisson equations. The long-range gravitationally attractive interaction allows the…