Quantum Effects of Bose-Einstein Condensates

In this paper,we study quadrature squeezings of two Bose-Einstein condensates with collision and non- classical properties of pair entanglement in four wave mixing in Bose-Einstein condensates.With the aid of a numerical method,we find that the two modes(pair entanglement modes)α_1 and α_2 may exhibit quadrature squeezing,in which they are affected by the initial phase.It is shown that the two pump modes exhibit the same super-Poissonian distri- bution.The analysis for the mode-mode correlation shows that there always exists a violation of the Cauchy-Schwartz inequality,which means that correlation between the two pump modes is nonclassical.

Tunneling Dynamics of the Halves of a Double-Well Trap Containing a Bose-Einstein Condensate

In this paper, we have studied tunneling dynamics of the halves of a double-well trap containing a Bose-Einstein condensate. It is found that there exist step structure and macroscopic quantum self-trapping of population difference of atoms, and exist Shapiro-like steps of atomic tunneling current. Both the population difference and the atomic tunneling current depend strongly on the total number of atoms and the initial phase difference.

Tunneling Dynamics of Two—Species Bose—Einstein Condensates

We have studied the tunneling dynamics of two-species Bose-Einstein condensates. It is shown that the population difference and the Josephson-like tunneling current between the two condensates exhibit oscillation behaviors and there exists macroscopic quantum self-trapping, which strongly depends on the initial state, interatomic nonlinear self-interaction, interspecies nonlinear interaction, and the total number of atoms in the two condensates.

Interaction of F = 2 Spinor Bose Condensate with Driven External Magnetic Fields

In this letter, we have studied the interaction of F=2 spinor Bose condensate with a combination of staticand sinusoidal magnetic field bl(t) = b0 + bcos(ωt). We find that the tunneling current among spin 0 and spin ±l,spin 0 and spin ±2, spin ±1 and spin ±2 may exhibit the incremental oscillation behavior, which depends on the fieldparameters of the reduced amplitudes of the transverse and the longitudinal magnetic fields respectively. This meansthat the dynamics spin localization can be adjusted experimentally by selecting the less values of the reduced amplitudesof the transverse magnetic field bx/ω and those of the longitudinal magnetic field b/ω.

Interference of Atomic Bose-Einstein Condensate Interacting with Laser Field

Interference of an atomic Bose-Einstein condensate interacting with a laser field in a double-well potential with dissipation is investigated.If properly selecting the laser field and the initial states of the atoms in the two wells, we lind that the intensity exhibits revivals and collapses.The fidelity of interference is affected by the total number of atoms in the two wells and dissipation.

Influence of External Magnetic Fields on Tunneling of Spin-1 Bose Condensate

In this letter, we have studied the influence of the external magnetic fields on tunneling of the spin-1 Bose condensate. We find that the population transfer between spin-0 and spin-±1 exhibits the step structure under the external cosinusoidal magnetic field and a combination of static and cosinusoidal one, respectively. Compared with the longitudinal component of the external magnetic field, the smaller the transverse component of the magnetic field is, the larger the time scale of exhibiting the step structure does. The tunneling current may exhibit periodically oscillation behavior when the ratio of the transverse component of the magnetic field is smaller than that of the longitudinal component, otherwise it exhibits a damply oscillating behavior. This means that the dynamical spin localization can be adjusted by the external magnetic fields.