Shuangyuan Xie

Atom-atom interaction in an anisotropic photonic crystal

Abstract Spontaneous emission from two two-level atoms within an anisotropic photonic crystal is investigated when direct dipole-dipole interaction is taken into account. The radiation properties of the present two atoms system are similar to that of a V-type three-level atom embedded in an anisotropic photonic crystal. The direct dipole-dipole interaction can enhance or depress the spontaneous emission depending on the relative position of the upper levels from the band edge of the photonic crystals. Owing to quantum interference and the dipole-dipole interaction, the spontaneous emission spectra are complicated non-Lorentzian shapes and depend strongly on the relative position of the upper levels from the bandgap and the initial state of the system.

Spontaneous radiation from a V-type three-level atom in three-dimensional photonic crystals

The spontaneous radiation from a V-type three-level atom embedded in a photonic crystal with three-dimensional dispersion relation is studied. Due to no singularity in the density of states for the anisotropic case, the radiation field displays some novel behaviors, which are different from that for the isotropic case.

Atom–atom interaction in an anisotropic photonic crystal

Abstract Spontaneous emission from two two-level atoms with direct dipole–dipole interaction (DDDI) between them in an anisotropic photonic crystal is investigated. The DDDI can depress or enhance the spontaneous emission, depending on the relative position of the upper levels from the bandgap.

STATISTICS FOR q-COMMUTATOR IN THE CASE OF qs+1=1

In this letter, we introduce a new statistics to describe particles whose creation and annihilation operators satisfy the relation aa†-qa†a=1 in the case of qs+1=1.

ENTANGLEMENT CONTROLLING OF A THREE-LEVEL CASCADE ATOM INTERACTING WITH A TIME-DEPENDENT COHERENT FIELD

The interaction between a three-level cascade atom and an initial coherent field with a time-varying frequency has been investigated, including the dynamic behavior of the atomic level occupation probabilities and the entanglement between the atom and the field. The frequency of the field is modulated in the forms of sine and rectangle. It is found that the field-frequency variation has a great influence on the properties of the generalized Jaynes-Cummings model. Appropriate frequency modulation can enhance and stabilize the degree of entanglement between the atom and the field.

Nonclassical properties of a time-varying Jaynes–Cummings model

The interactions between a two-level atom and a field with a time-varying frequency have been investigated. The two typical cases, the frequency of the field varying with time in the forms of sine and rectangle, have been considered. The dynamic behaviour of the field squeezing, photon antibunching and atomic dipole squeezing are investigated numerically as a function of time. A number of novel phenomena are discovered and discussed.

q-PHASE-COHERENT STATES AND THEIR SQUEEZING PROPERTIES

Some kinds of q-phase-coherent states of a q-harmonic osscillator in a finite-dimensional Hilbert space are constructed. Some properties of these states are discussed. Second-order squeezing properties of these states with respect to the phase quadrature operators are studied. The number-phase squeezing and number-phase uncertainty relations are also studied in detail for a two-state system. Some new number-phase minimum uncertainty states are found.