Pollack, S.E.Dries, D.Hulet, R.G.Magalhães, K.M.F.Henn, E.A.L.Ramos, E.R.F.Caracanhas, M.A.Bagnato, V.S.2015-03-302015-03-302010Pollack, S.E., Dries, D., Hulet, R.G., et al.. "Collective excitation of a Bose-Einstein condensate by modulation of the atomic scattering length." <i>Physical Review A,</i> 81, no. 5 (2010) American Physical Society: 53627. http://dx.doi.org/10.1103/PhysRevA.81.053627.https://hdl.handle.net/1911/79426We excite the lowest-lying quadrupole mode of a Bose-Einstein condensate by modulating the atomic scattering length via a Feshbach resonance. Excitation occurs at various modulation frequencies, and resonances located at the natural quadrupole frequency of the condensate and at the first harmonic are observed. We also investigate the amplitude of the excited mode as a function of modulation depth. Numerical simulations based on a variational calculation agree with our experimental results and provide insight into the observed behavior.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.Journal articlehttp://dx.doi.org/10.1103/PhysRevA.81.053627