Interference of Bose condensates: testing the paradigm of broken gauge symmetry

We studied theoretically the macroscopic interference of two independent Bose condensates released from a double potential trap. The observation of fringes could serve as a test for the paradigm of broken gauge symmetry. By numerical solution of the non-linear Schrِdinger equation in three dimensions, the consecutive stages of expansion, overlap and interference were investigated in order to facilitate the design of future experiments. It turns out that the period of the interference fringes grows linearly in time with a velocity inversely proportional to the initial distance of the two condensates.