1S-2S spectrum of a hydrogen Bose-Einstein condensate - art. no. 033611

We calculate the two-photon 1S-2S spectrum of an atomic hydrogen Bose-Einst ein condensate in the regime where the cold collision frequency shift domin ates the line shape. Wentzel-Kramers-Brillouin and static phase approximati ons are made to find the intensities for transitions from the condensate to motional eigenstates for 2S atoms. The excited-state wave functions are fo und using a mean field potential, which includes the effects of collisions with condensate atoms. Results agree well with experimental data. This form alism can be used to find condensate spectra for a wide range of excitation schemes.