Abstract

We have measured the resonant response of a Bose-Einstein Condensate of ⁸⁷Rb in a TOP magnetic potential corresponding to the lowest two excitations of the condensate. To achieve this we have developed a new technique for probing the excitation spectrum of a condensed Bose gas which excites the condensate by perturbing the magnetic trap spring constant 2%. As with optical spectroscopy, selection rules due to conservation of angular momentum dictate response of the condensate and this allows us to identify the angular momentum of the excitation. The excitation frequencies also depend on two-body interactions, which depends on the condensate number and trap frequency.

© 1996 Optical Society of America