Two-mode squeezing of a cavity field interacting with a three-level \ensuremath{\Lambda}-type atom is found for a field initially in a coherent state. Some phenomena are revealed, such as two-mode squeezing weaker than single-mode squeezing due to the mode coupling, and periodic recovery of squeezed states caused by two-photon processes.
We investigate the phenomena of single-mode and two-mode squeezing for a three-level atom and two modes. The field modes are initially taken in coherent states. The effects of detuning on these phenomena are studied for one-photon and two-photon interactions. The relation between the collapse and revival phenomena and single-mode and two-mode squeezing is shown. It is found that the two-mode squeezing is much more effective than the single-mode squeezing for the one-photon interaction. While for the two-photon interaction the reverse is true.
The behavior of the dipole moment of a three-level atom interacting with cavity fields of arbitrary detunings is investigated. The time evolution and squeezing conditions of the components and correlation function of the dipole moment are calculated for three cases: one-mode field and a \ensuremath{\Xi}-type atom initially in the upper state, two-mode field and a \ensuremath{\Lambda}-type atom initially in the upper state, and two-mode field and a \ensuremath{\Lambda}-type atom initially in one of the lower states. A number of interesting features are found and discussed.
Dynamics of a three-level atom interacting with one- and two-mode radiation fields is studied when the initial state of the field is a squeezed coherent state. All the three types of level configurations cascade; V and Lambda are considered. A model similar to the Jaynes-Cumming type developed by Yoo and Eberly1 is used. Various parameter ranges including the one in which the photon number distribution for the squeezed state exhibits oscillatory behavior2 are considered. Interesting revival structures are seen. Curves are presented to illustrate the behavior.
The generation and evolution of entanglement and squeezing for the two-mode fields are discussed in a cascade three-level atomic system. Two photons of a strong external pump field induce atomic coherence between the top and bottom levels. The dynamics of this system in the presence of cavity losses is studied. It is shown that entanglement and squeezing between the two modes increase initially, then decrease and eventually disappear. The periods of them are extended with the increasing of the pump field intensity. The effects of the cavity losses on squeezing and entanglement are also discussed.
We consider a single Rydberg atom having two degenerate levels interacting with the radiation field in a single-mode ideal cavity. The transition between the levels is carried out by a Λ-type degenerate two-photon process via a third level far away from single-photon resonance. At the start of interaction, the atom is considered to be in a coherent superposition of its two levels and the field in a coherent state. We study the dynamics of the atomic as well as the field states. The squeezing in the quadratures of atomic states can reach up to 100%. The cavity field evolves to a statistical mixture of two coherent fields with the phase difference between them decided by the interaction time. Analysis of entropies of the atom and the field shows that the two systems are dis-entangled periodically in certain cases.