Nondegenerate Two-photon Jaynes-Cummings Model Research Articles

对相干态光场中非简并双光子Jaynes-Cummings模型的辐射谱和腔场谱

对相干态光场中非简并双光子Jaynes-Cummings模型的辐射谱和腔场谱

Dynamics of Bell nonlocality in non-degenerate two-photon Jaynes-Cummings model

We investigate quantum nonlocality dynamics of a three-level atom and a class of two-mode non-classical states (including the entangled coherent state, the pair coherent state and the two-mode squeezed state) in the non-degenerate two-photon Jaynes-Cummings model. It is shown that the time evolution of the Bell nonlocality for the case of the entangled coherent state is closely related to the average number of photons in the two-mode field. For the cases of the pair coherent state and the two-mode squeezed state, the effect of Bell nonlocality sudden death is demonstrated, and the absolute value of the 〈BCHSH〉 exhibits exact periodic collapses and revivals.

Quantum interference in the cavity field spectra of nondegenerate two-photon Jaynes-Cummings model

The cavity field spectra of two modes field both in the binomial state interacting with a two-level atom in an ideal cavity is investigated. The results for the weak initial fields are calculated. The influence of the quantum interference on the cavity field spectra is discussed. It’s shown that the quantum interference term performs periodical damped oscillation with the changing of the difference of the two field frequencies. The periodicity is about 016 g（g is the coupling coefficient between the atom and the fields）. When the difference of the two field frequencies is larger than 16 g, the quantum interference term can be ignored. Otherwise, the quantum interference term is related to photon number of initial field. The quantum interference term strengthens gradually with the photon number increasing, but weakens abruptly when the maximal photon number becomes greater than 4 The quantum interference phenomenon almost vanishes when the photon number is greater than 6.

Measurement Induced Enhancement of Squeezing inNondegenerate Two-Photon Jaynes–Cummings Model

Squeezing properties in the nondegenerate two-photonJaynes–Cummings model are investigated. The effects of direct selectiveatomic measurement and the application of the classical fieldfollowed by atomic measurement are analyzed. Different values ofthe parameters of the classical field are taken into account.It is found that the field squeezing can be enhanced bymeasurement.

Exact Solutions for Non-degenerate Two-Photon Jaynes–Cummings Model in the Presence of Dynamic Stark-Shifts

The exact solutions for the non-degenerate tow-photon Jaynes–Cummings model in the presence of the dynamic Stark-shifts are investigated. The Heisenberg equations of motion for the respective opera...

Combined effect of detuning and Stark shift on atomic dipole squeezing in nondegenerate two-photon processes

We investigate the generation of atomic dipole squeezing (ADS) in a nondegenerate two-photon Jaynes–Cummings model [S.C. Gou, Phys. Lett. A 147 (1990) 218] when the radiation field in a lossless cavity is initially in a two-mode squeezed vacuum state. It is found that if the atom is initially prepared in certain SU(2) coherent state, the detuning or Stark shift has a destructive effect on ADS pattern; while for the ground or excited atom, the detuning or Stark shift has a constructive effect which may generate irregular ADS pattern. However, the combined effect of the detuning and Stark shift could lead to regular and periodical ADS patterns no matter whether the atom is initially prepared in its ground, excited or SU(2) coherent states.

Generation of higher-order atomic dipole squeezing in a high-Q micromaser cavity. (V). A linear superposition of states

In our preceding paper, we investigated the generation of higher-order atomic dipole squeezing (HOADS) in a nondegenerate two-photon Jaynes–Cummings model in the absence of Stark shift. In this paper, we continue to study HOADS in this model but with the inclusion of Stark shift. Based on the linear superposition principle of quantum mechanics, we discuss the cases where the atom or the two-mode fields are initially prepared in a superposition of states. We demonstrate that the essential condition for generating HOADS is that the initial state of the system should include phase information, and HOADS cannot appear in atomic spontaneous radiation processes. The Stark shift brings time-dependent phase information into emitted photons and has a significant effect (constructively and destructively) on HOADS. It is found that weakly coupling of the intermediate virtual state to the ground state of the atom would lead to much more squeezing and collapse-revival phenomena. The relation between HOADS and second-order atomic dipole squeezing is also discussed.

Generation of higher-order atomic dipole squeezing in a high-Q micromaser cavity. (VII). Entangled two-mode coherent states

In our preceding paper V, we investigated the generation of higher-order atomic dipole squeezing (HOADS) in a nondegenerate two-photon Jaynes–Cummings model (NTPJCM) in the presence of Stark shift. In this paper, we continue to study HOADS in this model but focus on the specific cases that the radiation field is initially prepared in a two-mode entangled state (e.g., two-mode squeezed vacuum state, two-mode Perelomov and Barut–Girardello coherent states). It is found that increasing the fixed difference in the photon numbers of the two-mode entangled states of the radiation field could decrease the squeeze duration and shorten the squeeze period, and the detuning may lead to much effective HOADS by properly adjusting certain value. In general, the Stark shift has a destructive effect on HOADS, but the combined effect of the detuning and Stark shift could increase the squeeze duration and lead to regular and periodical HOADS pattern. The influence of atomic coherence on HOADS is also examined in detail.

Generation of higher-order atomic dipole squeezing in a high- Q micromaser cavity. (IV) Discussion of the nondegenerate two-photon Jaynes–Cummings model

The concept of higher-order atomic dipole squeezing (HOADS) was introduced in our previous paper (Physica A 246 (1997) 529) and developed in our recent works. In this paper, we consider the case of a two-level atom interacting with two-mode coherent fields in a high- Q micromaser cavity, i.e., a nondegenerate two-photon Jaynes–Cummings model (NTPJCM). Assuming that the radiation fields are initially in an uncorrelated coherent state, we investigate HOADS in the NTPJCM, including the discussion of the effects of the detuning and the phase difference between the uncorrelated coherent fields on HOADS. It is found that the higher-order quantum fluctuations in the absorptive part of the atomic dipole may go below the standard limit for the on- and off-resonance excitations if the phase difference between the uncorrelated coherent fields is adjusted properly. Especially, it shows a greater amount of squeezing in the resonant case. The relation between HOADS and second-order ADS is discussed.

Generation of pair and bi-pair coherent states

A method for the generation of pair coherent states of a two-mode cavity field is presented. It is based on the nondegenerate two-photon Jaynes-Cummings model. We also show how we can produce bi-pair coherent states of four modes located in two cavities using such a model.

Squeezing of an effective dipole in a non-degenerate two-photon Jaynes-Cummings model with Stark shift

The effective dipole squeezing (EDS) of a non-degenerate two-photon Jaynes-Cummings model (NTPJCM) is examined in presence of optical Stark shift. We consider the cases where (i) the atom, or (ii) the field is initially prepared in a superposition of states. It is shown that Stark shift has an additional feature apart from introducing an intensity dependent detuning — it induces phase sensitivity in the system. Further, for low values of the Stark parameter the squeezing follows the revival of Rabi oscillations. It is also shown that squeezing persists in certain intervals of time and does not depend on the initial phase of the atom field system.

Cavity field spectra of the nondegenerate two-photon Jaynes-Cummings model.

The cavity field spectra for various initial fields of a nondegenerate two-photon Jaynes-Cummings Model are investigated. It is shown that the two-peak structure due to the resonant interaction between a single two-level atom and two different mode fields inside a high-Q cavity persists for coherent and thermal cases. Moreover, coherent sidebands appear for a coherent field whose widths are governed by the field statistics. However, squeezed vacuum fields exhibit rather different features showing the classical resonance fluorescence spectra at large n\ifmmode\bar\else\textasciimacron\fi{} (even in two-photon transitions).

Atomic dipole squeezing and emission spectra of a nondegenerate two-photon Jaynes-Cummings model in the presence of Stark shift

The atomic dipole squeezing and the emission spectra in a nondegenerate two-photon Jaynes–Cummings model in the presence of Stark shift for various field inputs are studied. The percentage duration of the atomic dipole squeezing is greatly enhanced by the inclusion of the Stark shift. The emission spectra show an asymmetric central two-peak structure that is quite different from that in the absence of the Stark shift. When the fields are initially in the coherent state, asymmetric coherent sidebands emerge. The effect of atomic coherence on dipole squeezing and the emission spectrum have also been incorporated

Effective Dipole Squeezing in the Non-degenerate Two-photon Jaynes-Cummings Model with Superposition State Preparation

Abstract Effective dipole squeezing in the non-degenerate two-photon Jaynes-Cummings model for atom and fields initially prepared in superposition of states is investigated. It is shown that the squeezing can be exhibited in certain periods of time but it cannot be achieved for atomic spontaneous radiation processes.

Atomic-dipole squeezing and emission spectra of the nondegenerate two-photon Jaynes-Cummings model.

A nondegenerate two-photon Jaynes-Cummings model is analyzed for its atomic-dipole squeezing and emission spectra. The input fields are assumed to be coherent or squeezed. The atomic dipole squeezes both for the on- and off-resonance excitations, showing a greater amount of squeezing for the former. The emission spectrum shows a central-two-peak structure for a variety of field inputs. When the fields are initially in coherent or squeezed states, sidebands appear whose widths are governed by the input-field statistics.