Abstract

The production of Bose-Einstein condensates (RECs) of up to 10⁶ alkali atoms in magnetic Lraps has recently become sufficiently robust to allow experiments to probe BEC properties in detail. In particular, mechanical excitation of BECs of ⁸⁷Rb¹ and ²³Na² has been observed. The characteristic frequencies of free oscillation induced by “shaking” of a BEC agree well with the predictions of linearized mean-field theory for small-amplitude disturbances.³ However, there are observations of nonlinear response, manifested in the amplitude- dependence of normal mode frequencies,⁴ and a more general theoretical framework is required to explore the nonlinear regime.

© 1997 Optical Society of America