共查询到20条相似文献,搜索用时 15 毫秒
1.
YU Zhao-Xian WANG Ji-Suo JIAO Zhi-Yong 《理论物理通讯》2005,44(3):532-536
The interference of the two-component Bose-Einstein condensates with a coupling drive in the presence of the dissipation is studied. We find that when the two-component Bose-Einstein condensates are initially in the coherent states, for the smaller dissipation parameters compared with that of the rf frequency ωrf, the interference intensity exhibits damply oscillation behavior, whereas when the dissipation parameters are larger than that of the ωry, the interference intensity exhibits a fast attenuation behavior. As a comparison, the interference intensity in the absence of the dissipation is also studied. We conclude that the dissipation of the system can be evaluated by selecting the ωrf experimentally. 相似文献
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3.
Ronald Dickman 《Journal of statistical physics》1985,41(3-4):607-619
The coupled Boltzmann equations describing the evolution of the velocity distributions of a one-dimensional, two-component gas of Maxwellian molecules are analyzed. When the two species have different masses, the system approaches equilibrium. The complete eigenvalue spectrum of the linearized collision operator is obtained, and is found to exhibit an interesting dependence on the mass ratio. The response of one species to an external field, when the other species is regarded as a host fluid, is also examined. 相似文献
4.
P. J. Forrester 《Journal of statistical physics》1986,45(1-2):153-169
The Coulomb system consisting of an equal number of positive and negative charged rods confined to a line with the charges alternating in sign along the line is considered. By replacing the line with a lattice, one can calculate the grand partition function and correlations exactly for one value of the coupling constant. The exact solution exhibits features forbidden in the corresponding continuous system, in which each pair of oppositely charged rods also interact via a short-range repulsive potential, and there is no restriction on the ordering of the charges. The sum rule indicating the phase of the system is identified. 相似文献
5.
Yuan-Fa Cheng 《International Journal of Theoretical Physics》2003,42(12):2983-2990
The dynamics of two-component solitary waves in hydrogen-bonded chains in an external force and damping is investigated. The influence of the motion and the optical mode of the heavy ion sublattice on the portion sublattice is discussed. It will increase the soliton width and decrease the soliton mobility. The general expression for the kink soliton soliton is obtained. The velocity, the mobility and conductivity of the kink soliton are calculated. The results are in good agreement with the experimental data. 相似文献
6.
Effect of viscosity on stability and accuracy of the two-component lattice Boltzmann method with a multiple-relaxation-time collision operator investigated by the acoustic attenuation model
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A two-component lattice Boltzmann method (LBM) with a multiple-relaxation-time (MRT) collision operator is presented to improve the numerical stability of the single relaxation time (SRT) model. The macroscopic and the momentum conservation equations can be retrieved through the Chapman—Enskog (C-E) expansion analysis. The equilibrium moment with the diffusion term is calculated, a diffusion phenomenon is simulated by utilizing the developed model, and the numerical stability is verified. Furthermore, the binary mixture channel model is designed to simulate the sound attenuation phenomenon, and the obtained simulation results are found to be consistent with the analytical solutions. The sound attenuation model is used to study the numerical stability and calculation accuracy of the LBM model. The simulation results show the stability and accuracy of the MRT model and the SRT model under different viscosity conditions. Finally, we study the influence of the error between the macroscopic equation of the MRT model and the standard incompressible Navier—Stokes equation on the calculation accuracy of the model to demonstrate the general applicability of the conclusions drawn by the sound attenuation model in the present study. 相似文献
7.
P. J. Forrester 《Journal of statistical physics》1989,54(1-2):57-79
A study of the one-dimensional lattice gas of positive and negative charges interacting via the logarithmic potential is continued. The two-particle distribution functions are evaluated exactly at the couplings=2 and 4. It is proved that the=4 isotherm exhibits an insulator-conductor phase transition at the reduced density 1/2, and the scaling behavior of the correlations near this critical point is given. Similarities of the conjectured phase diagram with that of a one-dimensional one-component log-gas in a periodic potential are noted. 相似文献
8.
利用双模近似方法研究了一维双组分玻色-爱因斯坦凝聚体(Bose-Einstein condensates,BECs)的量子隧穿特性.从描述三维双组分BECs系统的Gross-Pitaevskii方程(GPE)出发,得到了描述一维体系的GP方程.把体系波函数写成原子数和相位指数的乘积,得到描述体系隧穿特性的费曼方程.数值求解费曼方程,研究了原子之间相互作用(双组分BECs体系原子之间的相互作用包括组分内部原子之间的相互作用和不同组分原子之间的相互作用)对隧穿特性的影响.结果显示,当原子之间的相互作用较弱时,体系发生量子隧穿现象,表现为原子数在平衡位置附近作周期振荡;随着原子之间相互作用增强,体系经历一个临界状态,进入自俘获状态,即由于原子之间相互作用的存在,在对称双势阱中演化的BECs可以呈现出原子数高度的不对称分布,好像绝大数原子被其中一个势阱俘获.从隧穿到自俘获原子之间的相互作用存在一个临界值,从而体系的能量也对应一个临界值,根据体系的哈密顿函数,就能求出相互作用临界值的表达式. 相似文献
9.
By making use of Duan--Ge's decomposition theory of gauge potential
and the topological current theory proposed by Prof. Duan
Yi-Shi, we study a two-component superfluid Bose condensed system,
which is supposed to be realized in the interior of neutron stars in
the form of the coexistence of a neutron superfluid and a protonic
superconductor. We propose that this system possesses vortex lines.
The topological charges of the vortex lines are characterized by the
Hopf indices and the Brower degrees of φ-mapping. 相似文献
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P. J. Forrester 《Journal of statistical physics》1984,35(1-2):77-87
The interpretation of the exact calculation of the partition function and correlations of a two-component plasma obtained earlier is considered. The system has species of charge ratio 12 which are constrained to lie on a circle and interact via the two-dimensional Coulomb potential. By studying the exact results we gain an understanding of why the excess thermodynamic quantities of the two component system can be well approximated by the sum of the appropriate excess thermodynamic quantities of the one-component systems. 相似文献
12.
研究了平面Bessel型光晶格(BL)中双组分玻色-爱因斯坦凝聚(BECs)体系的基态解.从描述三维(3D)BECs体系的动力学方程Gross-Pitaevskii方程(GPE)出发,当垂直方向囚禁频率远大于平面上囚禁频率时,得到了描述2D-BECs体系的动力学方程.利用双组分BECs体系中原子之间相互作用与BL强度相互平衡的条件,得到了平面BL光晶格中2D-GPE的一组基态精确解,给出了基态的原子数分布,总原子数和能量与原子之间相互作用强度及BL势的关系.相对于单组分BEC体系,由于不同组分原子相互作用的存在,使得BL光晶格中双组分BECs基态具有更丰富的结构.当不存在不同组分原子之间的相互作用时,模型简化到单组分体系,并给出了相应的基态解,原子数分布和能量.
关键词:
Bessel型光晶格
基态解
双组分玻色-爱因斯坦凝聚 相似文献
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Yuan-Fa Cheng Zhang Chen Shao-Min Chen 《International Journal of Theoretical Physics》2006,45(9):1677-1683
We study the nonlinear transport and the motion of the bell-shape soliton in hydrogen-bonded chains with asymmetric double-well potential, based on the new two-component soliton model. Solution, momentum, effective mass, width and energy of bell-shape soliton are found. The theoretical reasults are estimated and compared with experimental ones. The agreement between them is good. 相似文献
15.
Dynamics of vector solitons in two-component Bose--Einstein condensates with time-dependent interactions and harmonic potential
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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
16.
We investigate modulational instability (MI) of a coupled two-component Bose-Einstein condensates in a rotating ring trap. The excitation spectrum and the MI condition of the system are presented analytically. We find that the coupling between the two components strongly modifies the MI condition, and the MI condition is phase-dependent. Furthermore, we discuss the effect of MI on both density excitation and spin excitation. If the inter- and intra-component interaction strengths are all equal, the MI causes density excitation but not spin excitation, and if the inter- and intra-component interaction strengths are different, the MI causes both density excitation and spin excitation. Our results provide a promising approach for controlling the stability and excitation of a rotating two-component Bose-Einstein condensates by modulating its coupling strength and interaction strength. 相似文献
17.
In this paper, we are concerned with the explicit construction of peakon solutions of the integrable twocomponent system with cubic non-linearity. We establish the spectral and inverse spectral problem associated to the Lax pairs of the system. The inverse problem is solved by the classical results of Stieltjes continued fractions, which also contributes a lot to the spectral problem. The explicit formulas are obtained from solutions of the inverse problem. The positivity of the spectral measures is implied by J. Moser's work on the Jacobi spectral problem. 相似文献
18.
Impurity-induced localization of Bose-Einstein condensates in one-dimensional optical lattices
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The impurity-induced localization of two-component Bose-Einstein condensates loaded into deep one-dimensional optical lattices is studied both analytically and numerically.It is shown that,the analytical criteria for self-trapping and moving soliton/breather of the primary-component condensate are modified significantly by an admixture of an impurity component (the second component).The realization of the self-trapped state and the moving soliton/breather states of the primary-component becomes more easy with the minor admixture of the impurity-component,even if the two components are partly overlapped. 相似文献
19.
Wideband dispersion removal and mode separation of Lamb waves based on two-component laser interferometer measurement
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Ultrasonic Lamb waves are considered as a sensitive and effective tool for nondestructive testing and evaluation of plate-like or pipe-like structures. The nature of multimode and dispersion causes the wave packets to spread, and the modes overlap in both time and frequency domains as they propagate through the structures. By using a two-component laser interferometer technique, in combination with a priori knowledge of the dispersion characteristics and wave structure information of Lamb wave modes, a two-component signal processing technique is presented for implementing dispersion removal and mode separation simultaneously for two modes mixture signals of Lamb waves. The proposed algorithm is first processed and verified using synthetic Lamb wave signals. Then, the two-component displacements test experiment is conducted using different aluminum plate samples. Moreover, we confirm the effectiveness and robustness of this method. 相似文献
20.
本文运用数值模拟研究了二分量BEC原子数密度的长时间动力学行为,讨论了驱动场Rabi频率、二分量初始相对相位差、驱动场耦合强度、同分量内原子作用强度及不同分量间原子作用强度对阱中原子数密度演化特性的影响.结果表明:长时间内阱中原子数密度的演化出现与短时间内周期性余弦振荡不同的新现象,即呈现典型的量子崩塌与复苏. 相似文献