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141.
We consider rotational motion of an interacting atomic
Bose-Einstein condensate (BEC) with both two- and three-body
interactions in a quadratic-plus-quartic and harmonic-plus-Gaussian
trap. By using the variational method, the influence of the
three-body interaction and the anharmonicity of the trap on the
lowest energy surface mode excitation and the spontaneous shape
deformation (responsible for the vortex formation) in a rotating BEC
is discussed in detail. It is found that the repulsive three-body
interaction helps the formation of the vortex and reduces the lowest
energy surface mode frequency and the critical rotational frequency
of the system. Moreover, the critical rotational frequency for the
vortex formation in the harmonic-plus-Gaussian potential is lower
than that in the quadratic-plus-quartic potential. 相似文献
142.
143.
We show that the dark soliton of the Gross-Pitaevskii equation (GPE) that describes the Bose-Einstein condensate (BEC) density of a system of weakly repulsive bosons, also describes that of a system of strongly repulsive hard core bosons at half filling. As a consequence of this, the GPE soliton gets related to the magnetic soliton in an easy-plane ferromagnet, where it describes the square of the in-plane magnetization of the system. These relationships are shown to be useful in understanding various characteristics of solitons in these distinct many-body systems. 相似文献
144.
145.
We investigate the dynamics of bright matter wave solitons in spin-1 Bose–Einstein condensates with time modulated nonlinearities. We obtain soliton solutions of an integrable autonomous three-coupled Gross–Pitaevskii (3-GP) equations using Hirota?s method involving a non-standard bilinearization. The similarity transformations are developed to construct the soliton solutions of non-autonomous 3-GP system. The non-autonomous solitons admit different density profiles. An interesting phenomenon of soliton compression is identified for kink-like nonlinearity coefficient with Hermite–Gaussian-like potential strength. Our study shows that these non-autonomous solitons undergo non-trivial collisions involving condensate switching. 相似文献
146.
Xiao-Fei Zhang Zhi-Jing Du Ren-Bing Tan Rui-Fang Dong Hong Chang Shou-Gang Zhang 《Annals of Physics》2014
We consider a pair of coupled nonlinear Schrödinger equations modeling a rotating two-component Bose–Einstein condensate with tunable interactions and harmonic potential, with emphasis on the structure of vortex states by varying the strength of inter-component interaction, rotational frequency, and the aspect ratio of the harmonic potential. Our results show that the inter-component interaction greatly enhances the effect of rotation. For the case of isotropic harmonic potential and small inter-component interaction, the initial vortex structure remains unchanged. As the ratio of inter- to intra-component interactions increases, each component undergoes a transition from a vortex lattice (vortex line) in an isotropic (anisotropic) harmonic potential to an alternatively arranged stripe pattern, and eventually to the interwoven “serpentine” vortex sheets. Moreover, in the case of anisotropic harmonic potential the system can develop to a rotating droplet structure. 相似文献
147.
Nonlinear resonance phenomenon of one-dimensional Bose–Einstein condensate under periodic modulation 下载免费PDF全文
We investigate the effect of an external periodic modulation on the one-dimensional (1D) Bose-Einstein conden- sate with harmonic trapping potential. By numerically solving the Gross-Pitaevskii equation with symplectic algorithm, the nonlinear resonance phenomenon is shown and the corresponding Fourier spectrum is given. The autoresonance phe- nomenon is also presented under almost periodic external modulation, and it shows that the condensate eventually evolves into quasi-periodic oscillation. 相似文献
148.
Landau damping of collective mode in a quasi-two-dimensional repulsive Bose-Einstein condensate 下载免费PDF全文
We investigate the Landau damping of the collective mode in a quasi-two-dimension repulsive Bose-Einstein condensate by using the self-consistent time-dependent Hatree-Fock-Bogoliubov approximation and a complete and orthogonal eigenfunction set for the elementary excitation of the system.We calculate the three-mode coupling matrix element between the collective mode and the thermal excited quasi-particles and the Landau damping rate of the collective mode.We discuss the dependence of the Landau damping on temperature,on atom number in the condensate,on transverse trapping frequency and on the length of the condensate.The energy width of the collective mode is taken into account in our calculation.With little approximation,our theoretic calculation results agree well with the experimental ones and are helpful for deducing the damping mechanics and the inter-particle interaction. 相似文献
149.
150.