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1.
By using a multiple-scale method,we analytically study the effect of a localized impurity on the soliton dynamics in the Bose-Einstein condensates.It is shown that a dark soliton can be transmitted through a repulsive (or attractive) impurity,while at the position of the localized impurity the soliton can be quasitrapped by the impurity.Additionally,we find that the strength of the localized impurity has an important effect on the dark soliton dynamics.With increasing strength of the localized impurity,the amplitude of the dark soliton becomes bigger,while its width is narrower,and the soliton propagates slower. 相似文献
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Control of soliton characteristics of the condensate by an arbitrary x-dependent external potential 下载免费PDF全文
This paper presents a family of soliton solutions of the one-dimensional nonlinear Schrdinger equation which describes the dynamics of the dark solitons in Bose-Einstein condensates with an arbitrary x-dependent external potential.The obtained results show that the external potential has an important effect on the dark soliton dynamical characteristics of the condensates.The amplitude,width,and velocity of the output soliton are relative to the source position of the external potential.The smaller the amplitude of the soliton is,the narrower its width is,and the slower the soliton propagates.The collision of two dark solitons is nearly elastic. 相似文献
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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
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<正>We investigate the combined soliton solutions of two-component Bose—Einstein condensates with external potential. The "phase diagram" is obtained for the formation regions of different combined solitons.Our results show that the intraspecies(interspecies) interaction strengths and the external trapped potential clearly affect the formation of dark-dark, bright-bright,and dark-bright soliton solutions in different regions.Especially,we find that the bright-bright (dark-dark) soliton can exist in the case of both repulsive(attractive) intraspecies interaction strengths in the presence of external potential.This novel phenomenon is completely different from the formation of soliton solution of one-component Bose-Einstein condensates without external potential,and it will be useful for the study of two-component Bose-Einstein condensates. 相似文献
7.
Soliton dynamical properties of Boseben Einstein condensates trapped in a double square well potential 下载免费PDF全文
We first present an analytical solution of the single and double solitions of Bose-Einstein condensates trapped in a double square well potential using the multiple-scale method. Then, we show by numerical calculation that a dark soliton can be transmitted through the square well potential. With increasing depth of the square well potential, the amplitude of the dark soliton becomes larger, and the soliton propagates faster. In particular, we treat the collision behaviour of the condensates trapped in either equal or different depths of the double square well potential. If we regard the double square well potential as the output source of the solitons, the collision locations (position and time) between two dark solitons can be controlled by its depth. 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.
By developing multiple-scale method combined with
Wentzel--Kramer--Brillouin expansion, this paper analytically
studies the modulating effect of weakly periodic potential on the
dynamical properties of the Bose--Einstein condensates (BEC) trapped
in harmonic magnetic traps. A black--grey soliton transition is
observed in the BEC trapped in harmonic magnetic potential, due to
the weakly periodic potential modulating effect. Meanwhile, it finds
that with the slight increase of the weakly periodic potential
strength, the velocity of the soliton decreases, while its width
firstly decreases then increases, a minimum exists there. These
results show that the amplitude, velocity, and width of matter
solitons can be effectively managed by means of a weakly periodic
potential. 相似文献
10.
The stability of Bose--Einstein condensates (BECs) loaded into a
two-dimensional shallow harmonic potential well is studied. By using
the variational method, the ground state properties for interacting
BECs in the shallow trap are discussed. It is shown that the possible
stable bound state can exist. The depth of the shallow well plays an
important role in stabilizing the BECs. The stability of BECs in the
shallow trap with the periodic modulating of atom interaction by
using the Feshbach resonance is also discussed. The results show that
the collapse and diffusion of BECs in a shallow trap can be
controlled by the temporal modulation of the scattering length. 相似文献
11.
This paper develops the Hirota method carefully for applying into the growing model of quasi-one-dimensional Bose—Einstein condensations with attractive and repulsive interaction, respectively. After a tedious calculation it obtains the exact bright and dark soliton solutions analytically.
It shows that the growing model has the important effect on the soliton amplitude and the time-dependent potential only contributes to the phase and phase velocity. A detailed analysis for the asymptotic behaviour of two-soliton solutions shows that the collision of two soliton is elastic. 相似文献
12.
Controlling the collision between two solitons in the condensates by a double-barrier potential 下载免费PDF全文
We present an analytical solution of two solitons of Bose-Einstein condensates trapped in a double-barrier potential by using a multiple-scale method.In the linear case,we find that the stable spots of the soliton formation are at the top of the barrier potential and at the region of barrier potential absence.For weak nonlinearity,it is shown that the height of the barrier potential has an important effect on the dark soliton dynamical properties.Especially,in the case of regarding a double-barrier potential as the output source of the solitons,the collision spots between two dark solitons can be controlled by the height of the barrier potential. 相似文献
13.
We present several families of exact solutions to a system of
coupled nonlinear Schr\"{o}dinger equations. The model describes a
binary mixture of two Bose--Einstein condensates in a magnetic trap
potential. Using a mapping deformation method, we find exact
periodic wave and soliton solutions, including bright and dark
soliton pairs. 相似文献
14.
Nonlinear transport of Bose--Einstein condensates in a double barrier potential 总被引:1,自引:0,他引:1 下载免费PDF全文
The stable nonlinear transport of the Bose-Einstein condensates through a double barrier potential in a waveguide is studied. By using the direct perturbation method we have obtained a perturbed solution of Cross-Pitaevskii equation. Theoretical analysis reveals that this perturbed solution is a stable periodic solution, which shows that the transport of Bose-Einstein condensed atoms in this system is a stable nonlinear transport. The corresponding numerical results are in good agreement with the theoretical analytical results. 相似文献
15.
Stabilised bright solitons in Bose-Einstein condensates in an expulsive parabolic and complex potential 下载免费PDF全文
The exact solitonic solutions of the one-dimensional nonlinear Schr?dinger equation, which describes the dynamics of bright soliton in Bose—Einstein condensates with the time-dependent
interaction in an expulsive parabolic and complex potential, are obtained by Darboux transformation. The results show that one can compress a bright soliton into an assumed peak of matter wave
density by adusting the experimental parameter of the ratio of axial oscillation to radial oscillation or feeding parameter. Especially,when parameters satisfy the relation λ=2γ, the
soliton is stable with time evolution without changing its shape and amplitude. 相似文献
16.
This paper solves exactly a set of fully quantized coupled equations describing the quantum dynamics of quantum spins mixing in spin-1 Bose-Einstein condensates by deriving the exact explicit analytical expressions for the evolution of creation and annihilation operators. 相似文献
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Squeezing via coupling of Bose--Einstein condensates in a double-well potential with a cavity light field 下载免费PDF全文
Squeezing via the interaction between the cavity light field and the Bose Einstein Condensate (BEC) in a doublewell potential is considered within the context of the two-mode approximation. For the cavity light field initially in a coherent state, it is shown that by choosing appropriate parameters, quadrature squeezing of the cavity light field can be achieved and it exhibits periodic oscillation. We also study the case in which BEC is tuned to resonance by periodically modulating the trapping potentiaL and the quadrature squeezing of the cavity field exhibits periodic collapse and revival effect. Both analytic and numerical calculations are performed, and they are found to be in good agreement with each other. The result shows that the quantum statistical properties of the cavity light field can be manipulated by its coupling with the condensates in the double-well potential. On the other hand, dynamical properties of the condensates in the double-well potential will be reflected by the quadrature squeezing of the light field. 相似文献
19.
Nonautonomous dark soliton solutions in two-component Bose–Einstein condensates with a linear time-dependent potential 下载免费PDF全文
We report the analytical nonantonomous soliton solutions (NSSs) for two-component Bose-Einstein condensates with the presence of a time-dependent potential. These solutions show that the time-dependent potential can affect the velocity of NSS. The velocity shows the characteristic of both increasing and oscillation with time. A detailed analysis for the asymptotic behavior of NSSs demonstrates that the collision of two NSSs of each component is elastic. 相似文献
20.
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