Bose-Einstein condensation of lithium

Randall G. Hulet, C.C. Bradeley, Charles A. Sackett +1 more

Charles A. Sackett, C. C. Bradley, Matthias Welling +1 more

Cheng Chin, Selim Jochim, M. Bartenstein +5 more

We achieve Bose-Einstein condensation of lithium molecules. The molecules are formed by pairing fermionic lithium atoms and they are evaporatively cooled to BEC in an optical dipole trap

C. C. Bradley, Charles A. Sackett, Randall G. Hulet

The initial evidence for Bose-Einstein condensation (BEC) of $^{7}\mathrm{Li}$ consisted of image distortions that suddenly appeared as the gas was evaporatively cooled to near the transition temperature. We present results of a model of the imaging system used to produce these images. The model confirms that the distortions are a sensitive indicator of BEC, but shows that they make quantitative analysis difficult. We find that the distortions resulted from light scattered by the condensate, in conjunction with aberrations in the imaging lens.

Randall G. Hulet, Curtis C. Bradley, Charles A. Sackett

Bose-Einstein condensation of 7Li has been studied in a magnetically trapped gas. Because of the effectively attractive interactions between 7Li atoms, many-body quantum theory predicts that the occupation number of the condensate is limited to about 1400 atoms. We observe the condensate number to be limited to a maximum value between 650 and 1300 atoms. The measurements were made using a versatile phase-contrast imaging technique. We discuss our measurements, the current theoretical understanding of BEC in a gas with attractive interactions, and future experiments we hope to perform.