Abstract

Since 1995 several groups have observed Bose-Einstein condensation in ultracold atomic gases. The condensates are obtained by evaporative cooling of atoms in magnetic traps, with critical temperatures in the range 20nK-1μK, and have been prepared with up to 10⁷ particles. These systems are ideal to study the properties of condensates: they are very dilute so that the interactions do not prevent from getting a fraction of condensed atoms close to unity contrarily to the case of liquid helium. Interactions however must be included below the critical temperature to determine the correct condensate wave function: this can be done with the standard non-linear Schrodinger equation (Gross-Pitaevskii equation).

© 1998 IEEE