article published Mattias Gustavsson author Elmar Haller author Manfred Mark author Johann G Danzl author 42EFD3B6-F248-11E8-B48F-1D18A9856A870000-0001-8559-3973 Russell Hart author Andrew Daley author Hanns Nägerl author The phenomenon of matter-wave interference lies at the heart of quantum physics. It has been observed in various contexts in the limit of non-interacting particles as a single-particle effect. Here we observe and control matter-wave interference whose evolution is driven by interparticle interactions. In a multi-path matter-wave interferometer, the macroscopic manybody wave function of an interacting atomic Bose-Einstein condensate develops a regular interference pattern, allowing us to detect and directly visualize the effect of interaction-induced phase shifts. We demonstrate control over the phase evolution by inhibiting interaction-induced dephasing and by refocusing a dephased macroscopic matter wave in a spin-echo-type experiment. Our results show that interactions in a many-body system lead to a surprisingly coherent evolution, possibly enabling narrow-band and high-brightness matterwave interferometers based on atom lasers. IOP Publishing Ltd.2010 eng 10.1088/1367-2630/12/6/065029 12 yes M. Gustavsson, E. Haller, M. Mark, J.G. Danzl, R. Hart, A. Daley, H. Nägerl, New Journal of Physics 12 (2010). M. Gustavsson <i>et al.</i>, “Interference of interacting matter waves,” <i>New Journal of Physics</i>, vol. 12. IOP Publishing Ltd., 2010. Gustavsson, Mattias, et al. “Interference of Interacting Matter Waves.” <i>New Journal of Physics</i>, vol. 12, IOP Publishing Ltd., 2010, doi:<a href="https://doi.org/10.1088/1367-2630/12/6/065029">10.1088/1367-2630/12/6/065029</a>. Gustavsson M, Haller E, Mark M, Danzl JG, Hart R, Daley A, Nägerl H. 2010. Interference of interacting matter waves. New Journal of Physics. 12. Gustavsson, M., Haller, E., Mark, M., Danzl, J. G., Hart, R., Daley, A., &#38; Nägerl, H. (2010). Interference of interacting matter waves. <i>New Journal of Physics</i>. IOP Publishing Ltd. <a href="https://doi.org/10.1088/1367-2630/12/6/065029">https://doi.org/10.1088/1367-2630/12/6/065029</a> Gustavsson M, Haller E, Mark M, et al. Interference of interacting matter waves. <i>New Journal of Physics</i>. 2010;12. doi:<a href="https://doi.org/10.1088/1367-2630/12/6/065029">10.1088/1367-2630/12/6/065029</a> Gustavsson, Mattias, Elmar Haller, Manfred Mark, Johann G Danzl, Russell Hart, Andrew Daley, and Hanns Nägerl. “Interference of Interacting Matter Waves.” <i>New Journal of Physics</i>. IOP Publishing Ltd., 2010. <a href="https://doi.org/10.1088/1367-2630/12/6/065029">https://doi.org/10.1088/1367-2630/12/6/065029</a>. 10462018-12-11T11:49:51Z2021-01-12T06:47:53Z