Pollack, S.E.Dries, D.Junker, M.Chen, Y.P.Corcovilos, T.A.Hulet, R.G.2015-03-302015-03-302009Pollack, S.E., Dries, D., Junker, M., et al.. "Extreme Tunability of Interactions in a Li7 Bose-Einstein Condensate." <i>Physical Review Letters,</i> 102, no. 9 (2009) American Physical Society: 90402. http://dx.doi.org/10.1103/PhysRevLett.102.090402.https://hdl.handle.net/1911/79451We use a Feshbach resonance to tune the scattering length a of a Bose-Einstein condensate of Li7 in the |F=1,mF=1⟩ state. Using the spatial extent of the trapped condensate, we extract a over a range spanning 7 decades from small attractive interactions to extremely strong repulsive interactions. The shallow zero crossing in the wing of the Feshbach resonance enables the determination of a as small as 0.01 Bohr radii. Evidence of the weak anisotropic magnetic dipole interaction is obtained by comparison with different trap geometries for small a.engArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.Extreme Tunability of Interactions in a Li7 Bose-Einstein CondensateJournal articlehttp://dx.doi.org/10.1103/PhysRevLett.102.090402