Geometric Phase in the Interaction Between Three-energy Level Atom with New-type Radiation Field

In this letter, we have given the density operator of quantum interference of many atoms in spinor Bose-Einstein condensates.     

Imaginary Photon Field Effect in the Interaction System of Multi-atom with Single-mode Photon Field

By using the Lewis–Riesenfeld invariant theory, we have studied the dynamical and the geometric phases in the interaction system of multi-atom with single-mode photon field with imaginary photon process. We find that the geometric phases in a cycle case have nothing to do with the frequency of the photon field, the coupling coefficient between photons and atoms, and the atom transition frequency. If we use the more accuracy device, the geometric phases in the imaginary photon process may be observed, and the geometric phases in this process have the observable physical effect.     

Geometric Phase in a Time-Dependent Coupled Atom-Heteronuclear-Molecule Condensate

The geometric phase in a time-dependent coupled atom-heteronuclear-molecule condensate is investigated, and the disappearing condition of the geometric phase is given.     

Quantum Tunneling of a Dipolar Bose-Einstein Condensate in Optical Lattice

We study quantum tunneling of a dipolar Bose-Einstein condensate in optical lattice when the spin system initially is prepared in a squeezed coherent state. It is found that there exists quantum tunneling between lattices l and l ＋ 1, l and l - 1, respectively. In particular, when the optical lattice is infinitely long and the spin excitations are in the long-wavelength limit, quantum tunneling disappears between lattices l and l ＋ 1, and that l and l - 1. Correspondingly, the magnetic soliton appears.     

Quantum Effects of Many Atoms in Spinor Bose-Einstein Condensates

We have studied the evolutions of the population transfer, tunnelling current and antibunching effects between spin-（＋1） and spin-（-1） in the case of the strong laser pulses. It is found that the population transfer and tunnelling current exhibit periodical oscillation. For the same Rabi frequency, the larger the atom number, the longer the oscillation period is. For the spin-（-1） component, when the atomic numbers are N=4 and 10, the antibunching effect can appear. For different atomic numbers, the appearing regions are very different. For spin component ＋1, the antibunching effect can always appear for different atomic numbers.     

Coulomb Blockade and Quantum Fluctuation of a Nondissipative Mesoscopic Capacitance Coupling Circuit with Source

The quantum mechanical effect of electric chargein a nondissipative mesoscopic capacitance couplingcircuit is studied and the condition for Coulombblockade (CCB) is derived. It is pointed out that the CCB is related not only to the junctioncapacitance, but also to the inductance. The quantumfluctuation of this circuit is also discussed.     

Geometric Phase in a Generalized Time-Dependent Double-Boson Interaction Model

By using of the invariant theory and the large quantum numbers approximation, we have studied a generalized time-dependent double-Boson interaction model, the dynamical and geometric phases are given, respectively. The Aharonov-Anandan phase is also obtained under the cyclical evolution.     

Quantum Tunneling in an Order-Parameter-Preserving Antiferromagnet

We have studied quantum tunneling in an order-parameter-preserving antiferromagnet with the help of Holstein-Primakoff transformation. It is found that, when the system being prepared in a coherent state, there exist the quantum tunneling between lattices k and k+1, k and k−1, respectively. In particular, when the lattice is infinitely long and the spin excitations are in the long-wavelength limit, quantum tunneling disappear between lattices k and k+1, and that k and k−1, in this case the magnetic soliton appears.     

Tunneling of a Dipolar Bose–Einstein Condensate in an Optical Lattice

We have studied the tunneling and fluctuations of a dipolar Bose–Einstein condensate in an optical lattice, it is found that there exist the tunneling and fluctuations between lattices l and l+1, l and l−1, respectively. In particular, when the optical lattice is infinitely long and the spin excitations are in the long-wavelength limit, tunneling effects disappear between lattices l and l+1, and that l and l−1, in this case the fluctuations are a constant, and the magnetic soliton appears.     

Fidelity of Interference Between Two Bose-Einstein Condensates with Collision and Dissipation

Interference between the two Bose-Einstein condensates with collision and dissipation is investigated. Itis found that when the two condensates are initially in the coherent state, the interference intensity is affected by thecollision and dissipation, but for the initial Fock state, it is only related to the dissipation. Whether the initial stateis in the coherent state or in a Fock state, the fidelity time has nothing to do with collision. For the initial coherentstate, the fidelity loss rate is zero, but for the initial Fock state, it is determined by the initial particle number of thetwo condensates and dissipation.