Semiclassical stability analysis of a two-photon laser including spatial variation of the cavity field

We investigate the dynamics of a two-photon laser under conditions where the spatial variation of the cavity field along the cavity axis is important. Main attention is paid to linear stability analysis and numerical investigation of a two-photon laser for the Maxwell-Bloch equations. The model assumes pumping to the upper state of the two-photon transition. We consider the Maxwell-Bloch equations on the basis of which we study the stability analysis of the steady state of the system. The system is taken to be contained in a ring-laser cavity. Asymptotic expansion of the eigenvalue and analytic information are obtained in some realistic limits, such as very large reflectivity, very small cavity losses, or very small population relaxation rate. The results are illustrated with an application to a specific atomic system (Potassium) as an amplifying medium.Comment: 17 pages, 3 figure

Engineering entanglement of a general three-level system interacting with a correlated two-mode nonlinear coherent state

In this article a treatment of a three-level atom interacting with two modes of light in a cavity with arbitrary forms of nonlinearities of both the fields and the intensity-dependent atom-field coupling is presented. A factorization of the initial density operator is assumed, with the privileged field modes being in a pair-coherent state. We derive and illustrate an exact expression for the time evolution of the density operator, by means of which we identify and numerically demonstrate the region of parameters where significantly large entanglement can be obtained. We show that entanglement can be significantly influenced by different kinds of nonlinearities. The nonlinear medium yields the superstructure of atomic Rabi oscillation. We propose a generation of Bell-type states having a simple initial state preparation of the present system

A tentative approach to entanglement measures for a system of a three-level atom interacting with a quantized cavity-field

In this paper, an entanglement measure due to quasi-mutual entropy from initially entangled mixed states of a three-level atom interacting with a single cavity field is introduced. Detailed analytical and explicit expressions are given taking into account an arbitrary form of the intensity-dependent coupling. Despite its simplicity the model exhibits a very broad range of intricate physical effects and it is widely used in quantized theories of laser. We show that quantum revivals are possible for a broad continuous range of physical parameters in the case of initial coherent states. Entanglement degree effects are shown to be very sensitive to the initial state of the system. Numerical calculations under current experimental conditions are taken into account and it is found that the intensity-dependent coupling changes the general features dramatically

Quantum effects due to the interaction between Su(1,1) and Su(2) quantum systems with damping

An analytical description is given for a model which represents the interaction between Su(1,1) and Su(2) quantum systems with Su(1,1) -cavity damping. The analytic solution for the master equation of the density matrix is obtained Then examinations of the effects of the damping parameter as well as the change in the initial state of the field on some physical phenomena are performed. Examination of the correlation function shows that the system displays anti-bunching for all periods of time except for a large value of the excitation number when k = 1 / 4. Our discussion for the variance squeezing also shows that the phenomenon of squeezing is pronounced in the quadrature variances for the even parity case

Generating non-locality correlation via 2-photon resonant interaction of dissipative two-qubit system with coherent field

In this paper, we introduce analytically the TC-model of two qubits interacting with a coherent cavity field via 2-photon process under the intrinsic dissipation effect. The interaction between the coherent cavity field and the two qubits, which are initially in an uncorrelated state, leads to generate non-locality qubit-qubit correlations. These correlations are investigated by using trace-norm measurement-induced nonlocality and Bures distance entanglement. It is found that the sudden appearance and sudden disappearance of the qubit-qubit entanglement depend not only on the intrinsic noise but also on the initial coherence intensity. The generated non-locality correlations and their stationary values may be controlled by the physical parameters of the intrinsic noise and the initial coherent field state

A moving three-level Λ-type atom in a dissipative cavity

In this paper, we consider a three-level Λ-type atom interacting with a two-mode of electromagnetic cavity field surrounded by a nonlinear Kerr-like medium, the atom and the field are suffering decay rates (i.e. the cavity is not ideal) when the multi-photon processes is considered. Also, the atom and the field are assumed to be coupled with a modulated time-dependent coupling parameter under the rotating wave approximation. The wave function and the probability amplitudes are obtained, when the atom initially prepared in the superposition states and the field initially in the coherent states, by solving the time-dependent Schrödinger equation by taking a proper approximation to the system of differential equations. An analytical expression of the atomic reduced density operator is given. We studied the degree of entanglement, between the field and atom, measure (DEM) via the concurrence, Shannon information entropy, momentum increment and diffusion, and finally we investigated the effects of decay rates and the time-dependent parameters on Husimi Q-function