The interaction between the laser cooled and trapped equidistant three-level atom (ion) and the quantized cavity field is investigated. The dipole moment matrix transition elements between the adjacent atomic energy levels d12 and d23 are assumed to be different. This model generalizes the problem of the pair of indistinguishable two-level atoms interacting with the squeezed vacuum which is equivalent to the equidistant three-level atom with equal dipole moment matrix transition elements. The exact analytical solution for the atom-field state-vector is found in the case in which at the initial moment t = 0, the single-mode cavity field is supposed to be in the squeezed vacuum state. With the help of this solution, the quantum-statistical and squeezing properties of the radiation field are studied. The obtained results are compared with those for the single two-level atom model. It should be noted that in the proposed model, the exact periodicity of the squeezing revivals is violated by the analogy with the single two-level atom one. The two limiting cases are analyzed. In the first limiting case in which d12 → d23 the quantum-statistical properties of the single-mode cavity field resemble those for the pair of indistinguishable two-level atoms. In the second one d12 → 0 the quantum-statistical and squeezing features of the proposed model are similar with those for the single two-level atom model.
We study the interaction between a single-mode electromagnetic field and a pair of indistinguishable two-level atoms via the intensity-dependent coupling. This problem is equivalent to the equidistant three-level atom with equal dipole moment matrix transition elements between the adjacent levels. The exact analytical solution for the atom–field state-vector is obtained assuming that at the initial moment the field is in the Holstein–Primakoff SU (1,1) coherent state. The quantum statistical and squeezing properties of the field are investigated. The results obtained are compared with those for the single two-level atom obtained by Buzek. We observe that the exact periodicity of the field squeezing that takes place in the case of the single two-level atom is violated in the case of the pair of cold atoms. That is, the exact periodicity of the physical quantities can be destroyed only if the radiation field interacts with a system of more than one two-level atom.
We study the interaction between the single-mode electromagnetic field and the pair of indistinguishable two-level atoms via the intensity-dependent coupling. This problem is equivalent to the equidistant three-level atom with equal dipole moment matrix transition elements between the adjacent levels. The exact analytical solution for the tom-field state- vector is obtained assuming that at the initial moment the field is in the Holstein-Primakoff SU (1,1) coherent state. The quantum-statistical and squeezing properties of the field are investigated. The obtained results are compared with those for the single two-level atom. It is observed that the exact periodicity of the field squeezing that takes place in the case of the single two-level atom is violated in the case of the pair of cold atoms. In other words, the exact periodicity of the physical quantities can be destroyed only if the radiation field interacts with a system of more than one two-level atom.
We study interaction between a pair of indistinguishable two-level atoms and the single-mode cavity field. It is supposed that the pair of two-level atoms is laser cooled and trapped into the ground vibrational state, in which vibrational quantum number
⟨nv⟩=0 . Two Jaynes–Cummings models are investigated. One is the Jaynes–Cummings model with intensity-dependent coupling and the another is the two-photon Jaynes–Cummings model of a pair of indistinguishable two-level atoms. It should be noted that in the present model, at initial moment
t=0 , in intensity-dependent Jaynes–Cummings model the cavity field is prepared in Holstein–Primakoff SU(1,1) CS, while in two-photon Jaynes–Cummings model it is prepared in the squeezed vacuum state. Moreover, at initial moment
t=0 , pair of atoms is supposed to be in the first excited state
∣e1⟩ in both models. By using exact analytical solutions for state-vectors of the coupled atom-field systems amplitude-squared squeezing of the quantized cavity field is examined as a function of the
∣ξ∣ parameter. In this situation, in both models higher-order squeezing has the tendency towards oscillations, but exact periodicity of these oscillations is violated by the analogy with the second-order squeezing.
We study the two-photon interaction between a three-level equidistant radiator (atom, molecule) with different dipole transitions and the single-mode cavity field. It is supposed that the three-level radiator is laser cooled and trapped into the ground vibrational state, in which the vibrational quantum number [Formula: see text]. In the proposed two-photon Jaynes–Cummings model (JCM) of a three-level atom at the initial moment [Formula: see text], the quantized cavity field is prepared in the squeezed vacuum state and the three-level radiator in the first excited state [Formula: see text]. By using the exact analytical solution for the state-vector of the coupled atom-field system, the amplitude-squared squeezing of the quantized cavity field is examined as a function of the [Formula: see text] and [Formula: see text] parameters. In this situation, higher-order squeezing has the tendency towards oscillations, but the exact periodicity of these oscillations is violated by the analogy with the second-order squeezing.
The statistical and fluctuational properties of an electromagnetic field in a nonideal cavity are studied with the help of the collective two-atom Jaynes-Cummings model taking into account losses of photons and spontaneous radiation of atoms into bath modes. For the coherent state of the field and excited initial state of atoms, the general analytical expressions for the second-order field correlation function, the second-order squeezing parameters, and the squared field amplitude are obtained by solving the master equation for the density matrix. The statistics and the degree of squeezing of the cavity field mode are studied as functions of the initial field intensity and of the coefficients of the energy dissipation of the system. It is shown that, for the two-atom dissipative model, compared to the single-atom model, the type of field statistics can be changed and the maximal degree of short-term squeezing can be increased.