Dynamics of BECs with Two- and Three-Body Interactions

Li, Guan-Qiang, Peng +5 more

Xiaobei Fan, Xueping Ren, Jing Wang +5 more

Abstract The dynamical behaviors of a quasi-2D Bose–Einstein condensate (BEC) with three-body interactions through a moving obstacle potential are studied numerically. Various vortex structures are discovered under different strength of three-body interactions when the two-body interaction is attractive or repulsive. When the width and moving velocity of the obstacle potential reach critical value, periodic anti-symmetric double-row vortex pairs will be released alternately in BEC, and a Bénárd–von Kármán (BvK) vortex street will be formed eventually. We noticed that the BvK vortex street can be excited when the three-body interactions are taken into account even if the two-body interaction is attractive. The mean value of the distance between two vortex rows to the distance between two vortex pairs in the same row is about 0.2. It is slightly smaller than the stability condition 0.28 without considering the three-body interaction. The parameter regions of vortex patterns at different three-body interaction are determined. It is found that an appropriate value of three-body interaction with larger velocity and lesser width is favorable to the formation of BvK vortex street. In a pair of point vortices, the distance and angular velocity between them are nearly invariant while they rotate around their center. The internal rule of vortex pair are also analyzed by calculating the drag force acting on the obstacle potential. Finally, we proposed an experimental protocol to realize the vortex street in 87Rb BEC with three-body interactions.

Javier von Stecher, Chris H. Greene

Emmanuel Kengne, Ahmed Lakhssassi

A one-dimensional (1D) Gross-Pitaevskii (GP) equation which governs the dynamics of Bose-Einstein condensates (BECs) with time-dependent scattering length in a harmonic potential is considered. Through a modified phase imprint transformation into the macroscopic order parameter, we suitably generate a derivative cubic-quintic Gross-Pitaevskii (DCQ-GP) equation that describes the dynamics of condensates in the harmonic potential for both twoand three-body interatomic interactions in the presence of nonlinear dispersion. Employing a modified lens-type transformation, we reduce the DCQ-GP equation into a derivative cubic-quintic Ginzburg-Landau (DCQ-GL) equation that allows us to investigate the modulational instability (MI) of the system and study, through the analytical exact solutions of the considered 1D GP equation, the effects of the three-body interactions and nonlinear dispersion on the dynamics of the BECs. We observe that for BECs with repulsive two-body interatomic interactions, the attractive three-body interactions and the nonlinear dispersion have opposite effects on the condensate: (i) The attractive three-body interactions enhance the instability, while the nonlinear dispersion softens the instability of the system; (ii) the attractive three-body interactions contributes to the ejections of atoms from the condensates while the nonlinear dispersion contributes to the accumulation of atoms in the condensates; (iii) the attractive three-body interactions contributes to the broadening of the matter wave solitons, while the nonlinear dispersion contributes to the compression of the matter wave solitons.

A. Gammal, Victo S. Filho, Lauro Tomio +1 more

Zhixia Wang, Xihe Zhang, Ke Shen

We investigate the dynamics of two tunnel-coupled Bose-Einstein condensates (BECs) in a double-well potential. The effects of the three-body recombination loss and the feeding of the condensates from the thermal cloud are studied in the case of attractive interatomic interaction. An imaginary three-body interaction term is considered and a two-mode approximation is used to derive three coupled equations which describe the total atomic numbers of the two condensates, the relative population and relative phase respectively. Theoretical analyses and numerical calculations demonstrate the existence of chaotic and hyperchaotic behaviour by using a periodically time-varying scattering length.