共查询到11条相似文献,搜索用时 46 毫秒
1.
CHEN Ai-xi DENG Li 《原子与分子物理学报》2006,23(B04):111-115
The theoretical investigation of quantum coherent atomic oscillations between two coupled Bose-Eimtein condensates(BECs) is studied. We apply the inseparable wave function of time-space to describe twotrapped BECs in a double-well magnetic trap. According to Thomas-Fermi approximation, dynamical equations ofthe interwell phase difference and population imbalance are obtained. Using numerical method, coherent atomictunneling and macroscopic quantum self-trapping(MQST) effect are investigated. 相似文献
2.
Nonadiabatic effects on population transfer of two Bose-Einstein condensates induced by atomic interaction 下载免费PDF全文
We investigate the stimulated Raman adiabatic passage for Bose-Einstein condensate (BEC) states which are trapped in different potential wells or two ground states of BEC in the same trap. We consider that lasers are nearly resonant with the atomic transitions. The difference of population transfer processes between BEC atoms and usual atoms is that the atomic interaction of the BEC atoms can cause some nonadiabatic effects, which may degrade the process. But with suitable detunings of laser pulses, the effects can be remedied to some extent according to different atomic interactions. 相似文献
3.
The theoretical investigation of quantum coherent atomic oscillations between two coupled Bose-Einstein condensates(BECs) is studied. We apply the inseparable wave function of time-space to describe two trapped BECs in a double-well magnetic trap. According to Thomas-Fermi approximation, dynamical equations of the interwell phase difference and population imbalance are obtained. Using numerical method, coherent atomic tunneling and macroscopic quantum self-trapping(MQST) effect are investigated. 相似文献
4.
理论上考察了两耦合玻色-爱因斯坦凝聚体间的相干原子振荡,我们用时空不能完全分离的波函数去描述囚禁在双磁阱中的玻色-爱因斯坦凝聚体,根据托马斯-费米近似,得到两凝聚体的相位差和布局数随时间的演化方程,应用数值计算的方法,考察了相干原子遂穿和宏观量子自囚禁效应.这些研究结果和采用双模时空分离波函数近似法得到的结果进行了比较. 相似文献
5.
The dynamics of triple-well trapped Bose-Einstein condensates with atoms feeding and loss effects 下载免费PDF全文
In this paper, we consider the macroscopic quantum tunnelling and self-trapping phenomena of Bose-Einstein condensates (BECs) with three-body recombination losses and atoms feeding from thermal cloud in triple-well potential. Using the three-mode approximation, three coupled Gross-Pitaevskii equations (GPEs), which describe the dynamics of the system, are obtained. The corresponding numerical results reveal some interesting characteristics of BECs for different scattering lengths. The self-trapping and quantum tunnelling both are found in zero-phase and :r-phase modes. Furthermore, we observe the quantum beating phenomenon and the resonance character during the self-trapping and quantum tunnelling. It is also shown that the initial phase has a significant effect on the dynamics of the system. 相似文献
6.
This paper obtains the energy-spectrum and eigenstate corrections of
two-mode Bose--Einstein condensates (BECs) coupled by quantum
tunnelling
by perturbation method in both strong and weak tunnelling
regions. The population imbalance between two BECs are then studied
in terms of the low-lying eigenstates which also characterize the
intrinsic entanglement between the two-mode BECs. The strong parity
effect in the weak tunnelling region is also investigated. 相似文献
7.
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. 相似文献
8.
Dynamics of vector solitons in two-component Bose--Einstein condensates with time-dependent interactions and harmonic potential 下载免费PDF全文
We present two kinds of exact vector-soliton solutions for
coupled nonlinear Schr?dinger equations with time-varying
interactions and time-varying harmonic potential. Using the
variational approach, we investigate the dynamics of the vector
solitons. It is found that the two bright solitons oscillate about
slightly and pass through each other around the equilibration state
which means that they are stable under our model. At the same time, we
obtain the opposite situation for dark--dark solitons. 相似文献
9.
Effect of interaction strength on gap solitons of Bose--Einstein condensates in optical lattices 下载免费PDF全文
We have developed a systematic analytical approach to the study on the dynamic properties of the linear and the nonlinear excitations for quasi-one-dimensional Bose-Einstein condensate trapped in optical lattices. A novel linear dispersion relation and an algebraic soliton solution of the condensate are derived analytically under consideration of Bose-Einstein condensate with a periodic potential. By analysing the soliton solution, we find that the interatomic interaction strength has an important effect on soliton dynamic properties of Bose-Einstein condensate. 相似文献
10.
A. Smerzi A. Trombettoni T. Lopez-Arias C. Fort P. Maddaloni F. Minardi M. Inguscio 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,31(4):457-461
We demonstrate, both from a theoretical and an experimental point of view, the possibility of realizing a weak coupling between
two Bose-Einstein condensates trapped in different Zeeman states. The weak coupling drives macroscopic quantum oscillations
between the condensate populations and the observed current-phase dynamics is described by generalized Josephson equations.
In order to highlight the superfluid nature of the oscillations, we investigate the response of a 87Rb non-condensate (thermal) gas in the same conditions, showing that the thermal oscillations damp more quickly than those
of the condensate.
Received 2 May 2002 / Received in final form 19 November 2002 Published online 6 March 2003
RID="a"
ID="a"e-mail: smerzi@sissa.it 相似文献
11.
Qiongtao Xie 《Physics letters. A》2009,373(2):173-176
We investigate the effect of a periodic nonlinearity on the self-trapping transitions of two weakly coupled Bose-Einstein condensates in a double well potential. By using an averaging method, the equations of motion of the slow dynamics are derived to analyze the self-trapping behavior. A new type of the tunneling dynamics, characterized by alternate appearance of self-tapping in the two wells, is observed when certain conditions are satisfied. 相似文献