Intensity-dependent Coupling Research Articles

Dynamical evolution of a five-level atom interacting with an intensity-dependent coupling regime influenced by a nonlinear Kerr-like medium

We present an analytical solution for a quantum system characterized by a double Λ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Lambda$$\\end{document} five-level atom interacting with an intensity-dependent coupling regime, influenced by a nonlinear Kerr-like medium. We also derive the constants of motion through Heisenberg’s equations. Furthermore, the dynamical evolution of the entanglement and quantum coherence between the atom and the field is discussed using linear entropy and l1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$l_{1}$$\\end{document}-norm of coherence. Through a comprehensive examination of the quantum system, it is observed that both the detuning and the Kerr-like parameters exert a significant impact on the degree of entanglement and coherence. However, the impacts of detuning and the Kerr effect become less pronounced when the photon multiplicity is high. In addition, we conduct a comparison between the five-level atomic system and a four-level system, revealing that the number of energy levels has a profound impact on the behavior of entanglement and coherence. These findings highlight the importance of atomic structure and photon multiplicity in controlling and optimizing quantum processes, particularly in applications involving quantum communication and information processing.

Exploring optical tomography dynamics for a dissipative coherent cavity in interaction with two-level atomic system

In this paper, we explore the optical tomography and quantum coherence dynamics for a coherent cavity field interacting with a two-level atom via intensity dependent coupling. We derive a specific solution to the master equation for the Jaynes–Cummings model, considering cavity damping. This solution reveals how the atom coherent-cavity interactions can produce new coherent states when the initial dissipative cavity-field state is coherent state or even coherent state. The effects of the atom-coherent-cavity interactions and the cavity damping, on the dynamics of the initial coherent state optical tomography and coherence is examined. In addition to the nonclassical properties, the atom-cavity interactions have a remarkable capacity to form distinct cavity field states linked to certain optical tomography distributions. Additionally, we investigate the maximal optical tomography dynamics for coherent state and even coherent state considering a range of cavity damping and detuning values.

The entanglement of a two two-level atoms interacting with a cavity field in the presence of intensity-dependent coupling regime, atom–atom, dipole–dipole interactions and Kerr-like medium

The entanglement of a two two-level atoms interacting with a cavity field in the presence of intensity-dependent coupling regime, atom–atom, dipole–dipole interactions and Kerr-like medium

Dynamics of phase space quasi-probability coherence of one of two moving atoms trapped in a cavity coherent field

This study explores the dynamics of atomic mixedness and phase space quasi-probability information of one of two moving atoms trapped in a cavity filled by a coherent field. The atom-photon interactions are considered with the resonance case through nonlinear intensity-dependent coupling. We investigate the impacts of the atom-photon and atomic motion couplings on the dynamics of the atomic Wehrl entropy's mixedness and phase space Husimi distribution information. By helping Wehrl entropy's mixedness dynamics, the dynamics of acceleration and enhancement of the generation of the atomic phase space quasi-probability coherence are examined, and the Husimi distributions of the generated atomic states of one of the two moving atoms are explored. The results are shown that the atomic Husimi distribution and Wehrl entropy's mixedness are susceptible to an increase in the atom-photon and the atomic motion couplings. Therefore, the atomic phase space Husimi distribution coherence can be improved by increasing the atomic motion and nonlinear atom-photon couplings.

Nonclassical correlations in lossy cavity optomechanics with intensity-dependent coupling

In this paper, we describe a double-optomechanical system which contains two lossy cavities, where each cavity includes a single-mode quantized field coupled to a single vibrational mode of a flexible membrane. There exists an interaction between a two-level atom and the cavity mode in the rotating wave approximation, with degenerate multi-photon transition in the presence of intensity-dependent coupling. Furthermore, we consider the effect of different sources of dissipation consisting of cavity decay, losses of cavity mirror, and spontaneous emission from the atom. We then start with the master equation to study the dynamics of considered quantum system. Afterward, we show that under some circumstances, the solution of the complicated problem via the master equation is reduced to the determination of the state vector in the time-dependent Schrödinger equation, with the help of an effective non-Hermitian Hamiltonian. Obtaining the explicit form of the state vector of the entire system, we study the nonclassical correlations of two atoms by means of geometric discord. We also examine the roles of intensity-dependent nonlinearity function, number of photons contributed to atomic transition, number of photons in the Fock states, and different sources of dissipation in the dynamics of geometric discord of the atoms. The numerical results indicate that the steady-state value of geometric discord can be revealed, and can appropriately be controlled via the mentioned-above effects. It can be found that the existence of spontaneous emission not only protects the nonclassical correlations of the atoms but also tends the geometric discord to a steady-state value.

Atom-field system: Effects of squeezing and intensity dependent coupling on the quantum coherence and nonclassical properties

Recently, Kumar Gerry et al. [Phys. Rev. A 90, 033427 (2014) https://doi.org/10.1103/PhysRevA.90.033427] studied the coherence control in a six-level atom through solving the Schrödinger equation in the field-interaction representation. In this manuscript, we investigate the interaction between a six-level atomic system (SLAS) and a single-mode field initially prepared in a squeezed coherent state. We extend the Jeans–Cummings model to describe the interaction between the atom and the squeezed field (SF) and the system dynamics. We examine the time evolution of the atomic coherence, non-local correlation, statistical properties within the bipartite system in the presence and absence intensity-dependent coupling (I-DC) for different squeezing regimes of the field.

Entanglement and Fisher Information for Atoms-Field System in the Presence of Negative Binomial States.

We developed a quantum scheme of two atoms (TAs) and field initially in a negative binomial state (NBS). We displayed and discussed the physical implications of the obtained results in terms of the physical parameters of the model. By considering that the TAs were initially prepared in a maximally entangled state, and that the single-mode field was in the NBS, the dynamics of quantum phenomena such TAs-field entanglement, TAs entanglement, and parameter estimation were examined. We found that the quantum quantifiers exhibited randomly quasi-periodic and periodic oscillations that depended on the success probability, photon number transition, and the intensity-dependent coupling effect. Furthermore, we analyzed the connection between the dynamical behavior of the quantifiers. This system can be compared with some other ones that are being discussed in the literature, in order to realize the quantum entanglement, and to control the precision of the parameter estimation.

Quantized study for asymmetric two two-level atoms interacting with intensity-dependent coupling regime

Quantized study for asymmetric two two-level atoms interacting with intensity-dependent coupling regime

Effect of intensity-dependent couplings and the atomic dissipation on the interaction of two three-level atoms and two modes of radiation field

The effect of intensity-dependent coupling and the atomic dissipation on the interaction of a pair of three-level atoms in the $$\Xi$$ configuration with a bi-mode cavity field are studied. The solution of the proposed model is obtained in the resonance case. Some statistical quantities are discussed to discover the characteristics of the model. With different nonlinearity functions, the population inversion and the photon number dynamics, which display the phenomenon of collapses and revivals are discussed. The non-classical effects by examining the Mandel Q-parameter are considered. The amount of correlation between the two atoms and the field is estimated by analyzing the results of the fidelity. The entanglement periods between the parts of the quantum system, the collapse and revival periods were affected by the choice of coupling intensity, where the collapse periods improved with increasing the effect of the Rabi frequency and decreased when the effect of the Rabi frequency decreased.

Entanglement, quantum correlations in a system of the two coupled atoms interacting with a thermal field under intensity-dependent coupling

Entanglement, quantum correlations in a system of the two coupled atoms interacting with a thermal field under intensity-dependent coupling

Two-qubit Fisher information and Jensen–Shannon nonlocality dynamics induced by a coherent cavity under dipole, intensity-dependent, and decoherence couplings

This study investigates two-qubit local quantum Fisher information correlation (LQFI), entanglement of formation (EoF), and two-qubit Jensen–Shannon coherence as a result of cavity–qubit coupling via intensity dependent and qubit–qubit interactions. Initially, the cavity is filled with coherent and even coherent fields, and the two-qubit state is pure. The cavity–qubit intensity dependent interaction, in the presence of intrinsic decoherence, can produce two-qubit local quantum Fisher information, entanglement of formation, and Jensen–Shannon coherence. This ability depends on dipole–qubit interactions, intrinsic decoherence, and initial cavity sates. The phenomena of sudden changes emerge in the dynamics behavior of the local quantum Fisher information, whereas the phenomenon of sudden birth–death occurs during the entanglement of formation dynamics. These phenomena can be enhanced by modifying the initial coherent field parameters, the mean photon number, and the non-classicality. The dipole qubit–qubit interaction improves the generated two-qubit correlation and coherence, while intrinsic decoherence decreases and stabilizes the generated two-qubit correlation and coherence. For a small initial coherent field intensity and dipole qubit–qubit interaction, the LQFI and EoF non-local correlations grow while the two-qubit Jensen–Shannon coherence diminishes. The qubit–qubit interaction coupling and the initial coherent field intensity can improve the produced stationary LQFI and EoF correlations and Jensen–Shannon coherence in the presence of the intrinsic decoherence.

A double Λ-five-level moving atom interacting with a two-mode field in the presence of damping and nonlinear Kerr medium

In this paper, we present the interaction between a five-level [Formula: see text]-configuration atom and a two-mode quantized field in the presence of the damping with the nonlinearity. According to the generalized nonlinear Jaynes–Cummings model (JCM) and the analytical solution of the Schrödinger equation, the general formula of the wave function for this system under special conditions, where the atom (the field) is initially prepared in the excited state (coherent state), has been found. Under some particular conditions, the five-level [Formula: see text]-type atom can be reduced to the three-level [Formula: see text]-type atom. Some physical aspects of the atom-field entangled state showing the entanglement degree, such as the field entropy. Moreover, we evaluate some of their non-classical statistical aspects such as atomic inversion. The effects of the physical parameters such as a Kerr medium, detuning parameter and the intensity-dependent coupling on the temporal behavior of the latter mentioned non-classical statistical aspects have been explored. We show that by choosing the evolved parameters in the interaction process, each of the above non-classical statistical features can be treated. We found that the parameters have an important influence on the properties of these phenomena.

Partial stability of induced entanglement in an off-resonance qutrit-cavity system with nonlinear coupling and intrinsic decoherence

In this article, we introduce an analytical description for the nonlinear off-resonance qutrit-cavity system through intensity-dependent nonlinear coupling under intrinsic decoherence. When the cavity is initially in coherent and even coherent states. The dynamics of the negativity entanglement, in the off-resonance qutrit-cavity system, is investigated under the physical parameters of the qutrit-cavity detuning, the intrinsic decoherence as well as the initial cavity coherent states. It is found that the ability of the off-resonance qutrit-cavity interaction to generate the entanglement, depends on the physical parameters. The high nonclassicality of the even coherent state can enhance the generated entanglement and its stability. For the intrinsic decoherence, the amount and the stability of the generated qutrit-cavity entanglement can be controlled by the coherent field intensity of the initial cavity states.

Interaction of a Three-Level Atom (Λ, V, Ξ) with a Two-Mode Field Beyond Rotating Wave Approximation: Intermixed Intensity-Dependent Coupling

Interaction of a Three-Level Atom (Λ, V, Ξ) with a Two-Mode Field Beyond Rotating Wave Approximation: Intermixed Intensity-Dependent Coupling

Underlying SUSY in a generalized Jaynes\u2013Cummings model

We present a general qubit-boson interaction Hamiltonian that describes the Jaynes–Cummings model and its extensions as a single Hamiltonian class. Our model includes non-linear processes for both the free qubit and boson field as well as non-linear, multi-boson excitation exchange between them. It shows an underlying algebra with supersymmetric quantum mechanics features allowing an operator based diagonalization that simplifies the calculations of observables. As a practical example, we show the evolution of the population inversion and the boson quadratures for an initial state consisting of the qubit in the ground state interacting with a coherent field for a selection of cases covering the standard Jaynes–Cummings model and some of its extensions including Stark shift, Kerr-like, intensity dependent coupling, multi-boson exchange and algebraic deformations.

Intrinsic decoherence effect on dynamics of a [formula omitted]-type qutrit interacting nonlinearly with a coherent field

In this paper, an intrinsic decoherence model is solved analytically for a Λ-type qutrit interacting with a coherent field through intensity-dependent coupling. The effects of the qutrit-cavity interaction, the intrinsic decoherence and the initial coherent field intensity are examined on some quantum phenomena as: atom population inversion, mixedness, entanglement as well as total correlation. It is found that the increase of the physical parameters, the regular oscillatory behavior of the qutrit-population collapses and revivals are changed remarkably. The interaction between the three-level atom and the coherent cavity field generates a strong mixture, negativity entanglement and total correlation (classical + quantum). The growth, the regularity and the stability of these quantum effects depend on the decoherence and the initial coherent cavity intensity.

Entanglement Dynamics Induced by a Squeezed Coherent Cavity Coupled Nonlinearly with a Qubit and Filled with a Kerr-Like Medium.

An analytical solution for a master equation describing the dynamics of a qubit interacting with a nonlinear Kerr-like cavity through intensity-dependent coupling is established. A superposition of squeezed coherent states is propped as the initial cavity field. The dynamics of the entangled qubit-cavity states are explored by negativity for different deformed function of the intensity-dependent coupling. We have examined the effects of the Kerr-like nonlinearity and the qubit-cavity detuning as well as the phase cavity damping on the generated entanglement. The intensity-dependent coupling increases the sensitivity of the generated entanglement to the phase-damping. The stability and the strength of the entanglement are controlled by the Kerr-like nonlinearity, the qubit-cavity detuning, and the initial cavity non-classicality. These physical parameters enhance the robustness of the qubit-cavity entanglement against the cavity phase-damping. The high initial cavity non-classicality enhances the robustness of the qubit-cavity entanglement against the phase-damping effect.

Mth Coherent State Induces Patterns in the Interaction of a Two-Level Atom in the Presence of Nonlinearities

Recently, the Mth coherent state (Mth CS) has been defined to be the resultant state of applying the number operator M times on the coherent state (CS) (Othman, Int. J. Theor. Phys. 58: 2451, 2019). In this article, we study the interaction between a two-level atom and a quantized single-mode field with intensity-dependent coupling in a Kerr medium. The Mth CS is assumed to be the interacting field with the atom. We study the dynamical behavior of the inversion, Q Mandel, linear squeezing, amplitude squared squeezing, and field entropy for different parameters and M values. We find that a certain pattern in the dynamics is induced with the Mth CS that is not present with the CS. We term this pattern as the “resolution phenomenon”. It is related to a semi-regular pattern being apparent in a specific region while after or before this region the pattern is overlapping. We also discover, in general, that the Mth CS of large M values for a given dynamic tends to have more periodicity, wider peaks, less growing/decaying rates, and more covering its range. Many other classical/nonclassical features are discussed for the concerning measurements. Finally, in the end, we propose some potential applications.

Intensity-dependent and multi-photon Hamiltonian of two two-level atoms and two-mode field in a Kerr medium solved by virtue of supersymmetric unitary transformation

We consider a generalized multi-photon interaction of two collectively two-level atoms with two-mode of electromagnetic field in the presence of Kerr medium and intensity-dependent coupling. We show that this atomic system possesses supersymmetric structure. We solved this system by virtue of supersymmetric unitary transformation. The supersymmetric generators of this atomic system are constructed. The diagonalization of the corresponding Hamiltonian is performed by introducing a supersymmetric unitary transformation. Accordingly, the eigenvalues and eigenfunctions of the Hamiltonian of the atomic system are obtained. The time evolution of the atom–field wave functions is derived in an exact form for two cases of the initial states of the atoms and the field modes. Some quantum effects such as the second-order correlation function, cross-correlation, purity and Husimi Q-function are investigated. The effects of the Kerr medium, detuning parameter, intensity-dependent coupling and multi-photon transition on the evolution of these quantum effects are examined. We conclude that the supersymmetric unitary transformation method is very simple and can be applied to a variety of atomic systems which possess a supersymmetric structure.

A two-photon laser in a Kerr-like medium with cross-Kerr and intensity-dependent coupling

We have studied the photon statistics of a nondegenerate two-photon laser with a medium that has both self- and cross-Kerr interactions as well as intensity-dependent atom–field coupling in the Hamiltonian. The density matrix equation of the atoms and two-mode cavity fields was derived using the standard Scully–Lamb approach and numerically solved. Under certain conditions, the photon distribution function equation was derived and solved analytically. The first few moments of photon numbers were calculated in the region above the lasing threshold. Nonclassicality of the fields was investigated by means of the Mandel Q parameter, second-order correlation functions and the Cauchy–Schwarz inequality. The results are analyzed for a range of finite Kerr parameters. Intensity-dependent coupling suppresses the nonclassicality of the field. It pushes the statistics of the field towards super-Poissonian.The self- and cross-Kerr interactions have significant roles in the nonclassicality of the two-photon cavity field and its statistics. These results are interesting for the field of quantum nonlinear optics and useful in quantum communications.