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Impurity driven Brownian motion of solitons in elon- gated Bose-Einstein Condensates



Ian B. Spielman, Lauren M. Aycock, Dina Genkina, Hsin I Lu, Hilary Hurst, Victor Galitski


Solitons, spatially-localized, propagating excitations resulting from an interplay be- tween nonlinearity and dispersion, are ubiquitous in physical systems from water channels1 and oceans2 to optical fibers3 and Bose- Einstein condensates (BECs)4. For the first time, we observed and controlled the Brownian motion5 of solitons. We launched lone, long-lived dark solitons in highly elongated 87Rb BECs and show that a dilute background of impurity atoms in a different internal state dramatically af- fects the soliton. With no impurities and in one- dimension (1-D), these solitons would have an infinite lifetime, a consequence of integrability?. The impurities scatter off the much larger soliton, contributing to its Brownian motion and decreasing its life- time. We describe the soliton’s diffusive behavior using a 1-D scattering theory of impurity atoms interacting with a soliton, giving diffusion coefficients consistent with experiment.
Nature Physics


Solitons, Bose Einstein condensates


Spielman, I. , Aycock, L. , Genkina, D. , , H. , Hurst, H. and Galitski, V. (2017), Impurity driven Brownian motion of solitons in elon- gated Bose-Einstein Condensates, Nature Physics, [online], (Accessed April 22, 2024)
Created March 7, 2017, Updated November 10, 2018