Center-of-mass motion as a sensitive convergence test for variational multimode quantum dynamics
Cosme, J.G.; Weiss, C.; Brand, J.
Multimode expansions in computational quantum dynamics promise convergence toward exact results upon increasing the number of modes. Convergence is difficult to ascertain in practice due to the unfavorable scaling of required resources for many-particle problems and therefore a simplified criterion based on a threshold value for the least occupied mode function is often used. Here we show how the separable quantum motion of the center of mass can be used to sensitively detect unconverged numerical multiparticle dynamics in harmonic potentials. Based on an experimentally relevant example of attractively interacting bosons in one dimension, we demonstrate that the simplified convergence criterion fails to assure qualitatively correct results. Furthermore, the numerical evidence for the creation of two-hump fragmented bright soliton-like states presented by A. I. Streltsov et al. [Phys. Rev. Lett. 100, 130401 (2008)] is shown to be inconsistent with exact results. Implications for understanding dynamical fragmentation in attractive boson systems are briefly discussed.
Cosme, J., Weiss, C., & Brand, J. (2016). Center-of-mass motion as a sensitive convergence test for variational multimode quantum dynamics. Physical Review A, 94(4), Article 043603. https://doi.org/10.1103/physreva.94.043603
|Journal Article Type||Article|
|Acceptance Date||Oct 3, 2016|
|Online Publication Date||Oct 3, 2016|
|Publication Date||Oct 3, 2016|
|Deposit Date||Oct 7, 2016|
|Publicly Available Date||Oct 7, 2016|
|Journal||Physical Review A|
|Publisher||American Physical Society|
|Peer Reviewed||Peer Reviewed|
Published Journal Article
Reprinted with permission from the American Physical Society: Physical Review A 94, 043603 © (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.
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