共查询到20条相似文献,搜索用时 21 毫秒
1.
We analyze the dynamics of a bright soliton in atomic scattering length in an expulsive parabolic potential. Bose-Einstein condensates (BECs) with time-dependent Under a safe ravage of parameters in which the Gross-Pitaevskii (GP) equation is effective in one dimension, our results show that, the dynamics of the bright soliton can be classed into two phases, depending on the value of the scattering length. Meanwhile, there exists a critical value of the absolute value of the atomic scattering length, below which, the dynamics of the bright soliton is very regular. Those phenomena can be useful for developing concrete applications of the nonlinear matter waves. We also obtain the orbital equation of the bright soliton and get some interesting data which may be useful for the experimental observation of the bright soliton and the application of the atom laser with manipulated intensity. 相似文献
2.
ZHANG Xiao-Fei ZHANG Pei YANG Qin 《理论物理通讯》2008,50(12):1323-1326
We obtain the integrable relation for the one-dimensional nonlinear Schrodinger equations which describes the dynamics of a Bos-Einstein Condensates with time-dependent scattering length in a harmonic potential. The exact one- and two-soliton solutions are constructed analytically by using the Hirota method. Then we further discuss the dynamics of the one soliton and the interactions between two solitons in currently experimental conditions. 相似文献
3.
We obtain the integrable relation for the one-dimensional
nonlinear Schrödinger equations which describes the dynamics
of a Bose-Einstein Condensates with time-dependent scattering
length in a harmonic potential. The exact one- and two-soliton
solutions are constructed analytically by using the Hirota method.
Then we further discuss the dynamics of the one soliton and the
interactions between two solitons in currently experimental
conditions. 相似文献
4.
WANG Tian-Yuan 《理论物理通讯》2009,51(2):255-258
We consider the one-dimensional nonlinear Schrǒdinger equations that describe the dynamics of a Bose-Einstein Condensates with time-dependent scattering length in a complex potential. Our results show that as long as the integrable relation is satisfied, exact solutions of the one-dimensional nonlinear Schrǒdinger equation can be found in a general closed form, and interactions between two solitons are modulated in a complex potential We find that the changes of the scattering length and trapping potential can be effectively used to control the interaction between two bright soliton. 相似文献
5.
LI Hua-Mei 《理论物理通讯》2007,47(1):63-68
Evolution of periodic waves and solitary waves in Bose-Einstein condensates (BECs) with time-dependent atomic scattering length in an expulsive parabolic potential is studied. Based on the mapping deformation method, we successfully obtain periodic wave solutions and solitary wave solutions, including the bright and dark soliton solutions.The results in this paper include some in the literatures [Phys. Rev. Lett. 94 (2005) 050402 and Chin. Phys. Left. 22 (2005) 1855]. 相似文献
6.
7.
In this paper, tunnelling dynamics of squeezed Bose-Einstein condensates (BEC's) in the presence of the nonlinear self-interaction of each species, the interspecies nonlinear interaction, and the Josephson-like tunnelling interaction is investigated by using the second quantization approach. The influence of BEC squeezing on macroscopic quantum self-trapping (MQST) and quantum coherent atomic tunnelling is analyzed in detail. It is shown that the MQST and coherent atomic tunnelling between two squeezed BEC's can be manipulated through changing squeezing amplitude and squeezing phase of BEC squeezed states. 相似文献
8.
We present three families of one-soliton solutions for (2+1)-dimensional Gross-Pitaevskii equation with both time-dependent scattering length and gain or loss in a harmonic trap. Then we investigate the dynamics of these solitons in Bose-Einstein condensates (BECs) by some selected control functions. Our results show that the intensities of these solitons first increase rapidly to the condensation peak, then decay very slowly to the background; thus the lifetime of a bright soliton, a train of bright solitons and a dark soliton in BECs can be all greatly extended. Our results offer a useful method for observing matter-wave solitons in BECs in future experiments. 相似文献
9.
Exact Analytical Solutions in Bose-Einstein Condensates with Time-Dependent Atomic Scattering Length
CHEN Yong LI Biao ZHENG Yu 《理论物理通讯》2007,47(1):143-148
In the paper, the generalized Riccati equation rational expansion method is presented. Making use of the method and symbolic computation, we present three families of exact analytical solutions of Bose-Einstein condensates with the time-dependent interatomic interaction in an expulsive parabolic potential. Then the dynamics of two anlytical solutions are demonstrated by computer simulations under some selectable parameters including the Feshbach-managed nonlinear coefficient and the hyperbolic secant function coefficient. 相似文献
10.
XIE Qiong-Tao 《理论物理通讯》2009,51(5):839-842
We investigate the self-tapping phenomena for two weakly coupled Bose-Einstein condensates with a rapid periodic modulation of the atomic scattering length. By using an averaging method, the equations of motion of the slow dynamics are derived to analyze the self-trapping behavior. It is shown numerically that under certain conditions, an alternative self-trapping in either well appears. 相似文献
11.
YUZhao-Xiao JIAOZhi-Yong 《理论物理通讯》2001,36(2):240-244
It is shown that the atomic tunneling current and the Shapiro-like steps strongly depend on the initial number of atoms in each condensate and the initial phase difference between the two condensates which are initially in even(odd) coherent states.The nonlinearity of interatomic interactions in the two condensates may lead to the atomic tunneling current and Shapiro-like step between the two condensates.It is found that the interatomic nonlinear interactions can induce the atomic tunneling current and Shapiro-like step between two condensates even though there does not exist the interspecies Josephson-like tunneling coupling.The static atomic tunneling current flows in positive or negative direction,which depends on the phase difference of the two-species condensates. 相似文献
12.
ZHANG Xiao-Fei XIE Chong-Wei WANG Shi-En 《理论物理通讯》2007,47(6):1063-1066
We obtain soliton and plane wave solutions for the coupled nonlinear Schrotinger equations, which describe the dynamics of the three-component Bose-Einstein condensates by using the Hirota method. Meanwhile we find that the system which has attractive atomic interaction will only possess a shape changing (inelastic) collision property due to intensity redistribution in the absence of the spin-exchange interaction. As a discussed example, we investigate the one-soliton, two-soliton solutions and collisional effects between bright two-soliotn solution, which lead to the intensity redistribu tion. 相似文献
13.
In this paper, we have studied the atomic population difference and the atomic tunneling current of twocomponent Bose-Einstein condensates with a coupling drive. It is found that when the two-component Bose-Einstein condensates are initially in the coherent states, the atomic population difference may exhibit the step structure, in which the numbers of the step increase with the decrease of the Rabi frequency and with the increment of the initial phase difference. The atomic population difference may exhibit collapses, and revivals, in which their periods are affected dramatically by the Rabi frequency and the initial phase difference. The atomic tunneling current may exhibit damping oscillation behaviors, and exist the step structure for the time range of 10-10 ~ 10-9 second. 相似文献
14.
LI Sheng-Chang DUAN Wen-Shan 《理论物理通讯》2008,50(9):655-660
For two-component disk-shaped Bose-Einstein condensates with repulsive atom-atom interaction, the small amplitude, finite and long wavelength nonlinear waves can be described by a Kadomtsev-Petviashvili-Ⅰ equation at the lowest order from the originai coupled Gross-Pitaevskii equations. One- and two-soliton solutions of the Kadomtsev- Petviashvili-1 equation are given, therefore, the wave functions of both atomic gases are obtained as well. The instability of a soliton under higher-order long wavelength disturbance has been investigated. It is found that the instability depends on the angle between two directions of both soliton and disturbance. 相似文献
15.
For two-component disk-shaped Bose-Einstein condensates with repulsive atom-atom interaction, the small amplitude, finite and long wavelength nonlinear waves can be described by a
Kadomtsev-Petviashvili-I equation at the lowest order from the original coupled Gross-Pitaevskii equations. One- and two-soliton solutions of the Kadomtsev-Petviashvili-I equation are given, therefore, the wave functions of both atomic gases are obtained as
well. The instability of a soliton under higher-order long
wavelength disturbance has been investigated. It is found that the
instability depends on the angle between two directions of both
soliton and disturbance. 相似文献
16.
HOU Jing-Min 《理论物理通讯》2007,48(6):1041-1046
We numerically simulate the dynamics of a spin-2 Bose-Einstein condensate. We find that the initial phase plays an important role in the spin component oscillations. The spin mixing processes can fully cancel out due to quantum interference when taking some
initial special phase. In all the spin mixing processes, the total spin is conversed. When the initial population is mainly occupied by a component with the maximal or minimal magnetic quantum
number, the oscillations of spin components cannot happen due to
the total spin conversation. The presence of quadratic Zeeman
energy terms suppresses some spin mixing processes so that the
oscillations of spin components are suppressed in some initial
spin configuration. However, the linear Zeeman energy terms have
no effects on the spin mixing processes. 相似文献
17.
CHEN Chang-Yong 《理论物理通讯》2004,41(4):547-552
Tunneling dynamics of multi-atomic molecules between atomic and multi-atomic molecular Bose-Einstein condensates with Feshbach resonance is investigated.It is indicated that the tunneling in the two Bose-Einstein condensates depends on not only the inter-atomic-molecular nonlinear interactions and the initial number of atoms in these condensates,but also the tunneling coupling between the atomic condensate and the multi-atomic molecular condensate.It is discovered that besides oscillating tunneling current between the atomic condensate and the multi-atomic molecular condensate,the nonlinear multi-atomic molecular tunneling dynamics sustains a self-locked population imbalance:a macroscopic quantum self-trapping effect.The influence of de-coherence caused by non-condensate atoms on the tunneling dynamics is studied.It is shown that de-coherence suppresses the multi-atomic molecular tunneling.Moreover,the conception of the molecular Bose-Einstein condensate,which is different from the conventional single-atomic Bose-Einstein condensate,is specially emphasized in this paper. 相似文献
18.
Zhi-Yuan Sun Yi-Tian Gao Xin Yu Ying Liu 《International Journal of Theoretical Physics》2011,50(9):2776-2789
We investigate compression of the bright bound solitons in the Bose-Einstein condensates (BECs) by exponentially increasing the absolute value of the atomic scattering length. Similarity transformation and Hirota bilinear method are used to symbolically solve the one-dimensional nonlinear Schrödinger equation with the time-dependent coefficients. We present types of the bright bound solitons in compression through manipulating their initial coherence. Results show that the improved quantity of the atomic density peaks can be observed before the collapse of the solitons when their coherence is increased. Furthermore, we discuss how those compressed bound solitons are influenced by the adjacent solitons. The bound structures in our study are illustrated to exist with the parameters within the current experimental capacity (the spatial and temporal ranges of the bound solitons are less than 56 μm and 50 ms in our investigation), which suggests a future observation in the BECs experiments. 相似文献
19.
The Rabi oscillations in two-component Bose-Einstein condensates with a coupling drive are studiedby means of a pair of bosonic operators. The coupling drive and initial phase difference will affect the amplitudeand the period of the Rabi oscillations. The Rabi oscillations will vanish in the evolution of the condensate densityfor some special initial phase differences (ψ = 0 or π). Our theory provides not only an analytical framework forquantitative predictions for two-component condensates, but also gives an intuitive understanding of some mysteriousfeatures observed in experiments and numerical. simulations. 相似文献
20.
JIAOZhi-Yong YUZhao-Xian YANGXin-Jian 《理论物理通讯》2004,42(2):229-234
In this paper, we have studied the atomic population difference and the atomic tunneling current of two-component Bose-Einstein condensates with a coupling drive. It is found that when the two-component Bose Einstein condensates are initially in the coherent states, the atomic population difference may exhibit the step structure, in which the numbers of the step increase with the decrease of the Rabi frequency and with the increment of the initial phase difference. The atomic population difference may exhibit collapses, and revivals, in which their periods are affected dramatically by the Rabi frequency and the initial phase difference. The atomic tunneling current may exhibit damping oscillation behaviors, and exist the step structure for the time range of 10^-10 ~ 10^-9 second. 相似文献