Weiss, C. and Cornish, S.L. and Gardiner, S.A. and Breuer, H.-P. (2016) 'Superballistic center-of-mass motion in one-dimensional attractive Bose gases : decoherence-induced Gaussian random walks in velocity space.', Physical review A., 93 (1). 013605.
We show that the spreading of the center-of-mass density of ultracold attractively interacting bosons can become superballistic in the presence of decoherence, via one-, two-, and/or three-body losses. In the limit of weak decoherence, we analytically solve the numerical model introduced in [Phys. Rev. A 91, 063616 (2015)]. The analytical predictions allow us to identify experimentally accessible parameter regimes for which we predict superballistic spreading of the center-of-mass density. Ultracold attractive Bose gases form weakly bound molecules, quantum matter-wave bright solitons. Our computer simulations combine ideas from classical field methods (“truncated Wigner”) and piecewise deterministic stochastic processes. While the truncated Wigner approach to use an average over classical paths as a substitute for a quantum superposition is often an uncontrolled approximation, here it predicts the exact root-mean-square width when modeling an expanding Gaussian wave packet. In the superballistic regime, the leading order of the spreading of the center-of-mass density can thus be modeled as a quantum superposition of classical Gaussian random walks in velocity space.
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|Publisher Web site:||http://dx.doi.org/10.1103/PhysRevA.93.013605|
|Publisher statement:||Reprinted with permission from the American Physical Society: Physical Review A 93, 013605 © (2016) by the American Physical Society. Readers may view, browse, and/or download material for temporary copying purposes only, provided these uses are for noncommercial personal purposes. Except as provided by law, this material may not be further reproduced, distributed, transmitted, modified, adapted, performed, displayed, published, or sold in whole or part, without prior written permission from the American Physical Society.|
|Date accepted:||06 December 2015|
|Date deposited:||25 January 2016|
|Date of first online publication:||08 January 2016|
|Date first made open access:||25 January 2016|
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