Vortices and interference in Bose-Einstein condensates

Frédéric Chevy

Ł. Dobrek, Mariusz Gajda, Maciej Lewenstein +3 more

We demonstrate numerically the efficient generation of vortices in Bose-Einstein condensates (BECs) by using a ``phase imprinting'' method. The method consists of passing a far-off-resonant laser pulse through an absorption plate with an azimuthally dependent absorption coefficient, imaging the laser beam onto a BEC, and thus creating the corresponding nondissipative Stark-shift potential and condensate phase shift. In our calculations we take into account experimental imperfections. We also propose an interference method to detect vortices by coherently pushing part of the condensate using optically induced Bragg scattering.

Nicholas G. Parker, B. Jackson, A. Martin +1 more

Kęstutis Staliūnas

It is shown that diffraction of Bose-Einstein condensates on a helical light grating results in vortices in the condensate. Helical light gratings can be produced by light interference of a Gaussian laser beam with a helical one. Diffraction orders of the Bose-Einstein condensate contain vortices of corresponding topological charge. The phenomena is illustrated by numerical integration of the Gross-Pitaevskii equation in two dimensions.

Haljan, ���������������������������������������������������������������������������������������� Anderson, Brian Matthews +3 more

Janne Ruostekoski, B. Kneer, W. P. Schleich +1 more

We theoretically study the coherent expansion of a Bose-Einstein condensate in the presence of a confining impenetrable hard-wall potential. The nonlinear dynamics of the macroscopically coherent matter field results in rich and complex spatiotemporal self-interference patterns demonstrating a nonlinear Talbot effect, and the formation of vorticity and solitonlike structures.