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?. For, 1?, as used for the data analysis shown in the main text, the amplitude is reduced by 18%. * current adressVienna Center for Quantum Science and Technology

?. , D. Hellweg, P. Ryytty, J. J. Arlt, W. Ertmer et al., Observation of Phase Fluctuations in Elongated Bose-Einstein Condensates, Phys. Rev. Lett, vol.87, issue.16, p.160406, 2001.

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