Population trapping in the Jaynes-Cummings model with a Kerr nonlinearity in the cavity

Abstract

An electromagnetic field state is found which maintains the population inversion of the atom stationary during the interaction with the field through a Jaynes-Cummings model (JCM) with a Kerr type nonlinearity in the cavity. The condition of stationarity of the population inversion includes the phase coupling of atomic dipole with the field. We have shown that the Kerr nonlinearity in the cavity field significantly modifies the photon statistics of the trapped field state through an intensity dependent detuning in the field compared to the normal JCM trapping state. We have also demonstrated the novel features of sub-Poissonian character and the squeezing of the trapped field state. The dynamics of the initial trapped field is studied in terms of squeezing and the Q-function.     

Polarization of radiation in multipole Jaynes-Cummings model

We discuss the spatial properties of quantum radiation emitted by a multipole transition in a single atom. It is shown that the polarization of multipole radiation and quantum fluctuations of polarization change with distance from the source. In the case of a transition specified by a given quantum number m, the quantum noise of polarization contains contributions coming from the modes with m' m as well.     

Cavity field spectrum for multiphoton Jaynes-Cummings model

Abstract

The field spectra in an ideal cavity for the multiphoton Jaynes-Cummings model are studied. The analytical expression for the spectrum is obtained from the finite double-Fourier transform of the two-time field correlation function. The spectral differences between the initial coherent and initial thermal states are discussed, and the comparisons between the field spectra and atomic emission spectra for k = 2, 3 and 4 are presented. It is shown that the kth power of the photon annihilation operator and atomic lowering operator are subjected to identical forms of a second-order differential equation, in which the coefficients consist of the constants of motion. The field spectrum in the cavity and the emission spectrum of the atom for the initial vacuum state are compared.     

Dynamics of the Jaynes-Cummings model in the presence of photonic crystals

The three-level atom Jaynes-Cummings model is solved exactly and its dynamics investigated in photonic crystals that exhibit band gaps. The atom-field coupling and the probability amplitudes are evaluated as functions of the mode frequency and for different cavity parameters. Besides band-gap effects, the system exhibits novel local field effects. These show as peaks in the atom-field coupling and hence peaks or dips in the probability functions.     

Quantum effects in the transient dynamics of a many mode Jaynes-Cummings model

Abstract

Phenomenology and mechanisms of energy exchange, due to induced atomic processes of absorption and emission, are investigated in the evolution of a two-mode Jaynes-Cummings model. One field mode is initially in a highly coherent populated state and the other one is initially empty. The field mode exchanges energy with the atom by two mechanisms, related to very different atomic dynamics, which operate in complementary phases of the system evolution. One mechanism determines the energy exchanges which involve only the populated mode and the atom. The other is responsible for mode-mode photon exchanges and becomes relevant when the first mechanism is quenched. Thus there is no competition between the atomic emission in the empty mode and processes involving the atom and the highly populated mode. Quantum features related to entanglement of atom and field states are discussed. Cooperative effects between the two field modes and their incompatibility with the predictions of neo-classical theory are evidenced.     

Thermal Equilibrium in the Jaynes-Cummings Model

Abstract

The master equation currently used to describe a two level atom interacting with a single mode field damped by contact with a thermal reservoir (the damped Jaynes-Cummings model) is shown not to have, as its steady state solution, the expected canonical density operator prescribed by the general principles of statistical mechanics for a system in thermal equilibrium. A modified master equation is derived here which satisfies this requirement. Except for a reservoir at zero temperature, this master equation differs from that which is currently used in that the damping terms contain contributions due to the atom-field interaction.     

Effects of Even and Odd Coherent States on the Evolution of the Two-photon Jaynes-Cummings model

We discuss the two-photon Jaynes-Cummings model prepared in even or odd coherent states in terms of its dynamical evolution and the statistical aspects of field, such as intensity-intensity correlation and squeezing. Time evolution of the quasiprobability function has also been investigated. This study reveals how the quantum interference present in the even and odd coherent states affects the nonlinear process of the two-photon transition.     

Counter-rotating Contributions in the Jaynes-Cummings Model

Abstract

We present several perturbative approaches to the Jaynes-Cummings model of optical resonance with the counter-rotating terms included. We find that there exists a hitherto overlooked phase-dependence of the atomic inversion which is due to an interference between the rotating wave and counter-rotating contributions.     

Construction of deformed photon-added nonlinear coherent states with negative m for the one-mode field in a Kerr medium

In this paper, based on the nonlinear coherent states formalism and using the Hamiltonian for a single mode field in a Kerr medium, the deformed photon-added nonlinear coherent states with negative m corresponding to the nonharmonic oscillators are constructed. In addition, some of the nonclassical properties associated with these states such as the Mandel parameter, quadrature squeezing and second-order correlation function are investigated. It is found that the deformed photon-added nonlinear coherent states with negative m for the one-mode field in a Kerr medium are nonclassical states.     

Multiphoton Jaynes-Cummings Model without the Rotating-wave Approximation

Abstract

The general time evolution of operators in the multiphoton Jaynes-Cummings model without the rotating-wave approximation is obtained. The contributions of the counter-rotating terms to atomic dynamics and field squeezing are examined in multiphoton processes.     

Non-classical Features in the Three-level Jaynes-Cummings Model

Abstract

The eigenfunctions and eigenenergies of the system composed of a cascade three-level atom and bichromatic or monochromatic field with arbitrary detunings are presented. The development of the state vector of the system with arbitrary initial conditions is obtained. The development of the quantum fluctuations and the second-order coherence degree for the field is calculated. The dependence of the squeezing and antibunching on the detunings, initial intensities and initial squeezing is studied. The contribution of single-photon and two-photon transitions to, and the influence of, the a.c. Stark effect on the squeezing are discussed.     

Squeezing of Spectral Components in the Jaynes-Cummings Model

Abstract

Squeezing of spectral components of a fluorescence field in the framework of the Jaynes-Cummings model has been studied. It has been shown that squeezing is observed only in sidebands of the fluorescence field. The degree of squeezing increases as the intensity of the cavity mode is increased. Contrary to squeezing in the cavity mode (see Kuklinski and Madajczyk [14] a large degree of squeezing in sidebands of the fluorescence field is observed in the short-time limit.     

New cavity-mode model for the dynamic Josephson tunneling states

A modified Fiske step model for Josephson tunneling states that includes a spatial variation of the dc Josephson current is studied. This spatial variation is due to the external current injected from the junction edges. The new model can explain both the Fiske step and zero-field current step (ZFCS) on an equal footing and can account for the symmetric mode recently obtained by one of the present authors (Chang) and his co-workers using computer simulation.     

Light Squeezing in the Jaynes-Cummings Model with Intensity-dependent Coupling

Abstract

We have found that in the intensity-dependent-coupling Jaynes-Cummings model with the coherent radiation field light squeezing exhibits periodical revivals. The influence of the initial states of the atom on the squeezing of light is investigated in detail.     

Dynamical Properties of the Field Phase in the Jaynes-Cummings Model

Abstract

Phase properties of a coherent field interacting with a two-level atom in an ideal cavity are studied using the new hermitian phase formalism of Pegg and Barnett. It is shown in particular that phase properties of the field reflect the collapse and revival phenomena. The effects of finite detuning and atomic coherences are treated. The results for the variance of the phase cosine are obtained and compared with those based on earlier approaches.     

Surface states simulation model for photoconductors infrared detectors

In the planer technology, the photoconduction response is greatly affected by the surface recombination phenomenon. The influence of surface defects on detection capabilities of photoconductors infrared detectors is analyzed. A model based on surface states associated of surface defects is also developed. In this model, the barrier height at the semiconductor free surface is modified under photonic excitation .The procedure used for calculation of such parameter has taken into account the depletion region and the influence of the photon wavelength (λ). The recombination of carriers at the semiconductor surface is also examined within the Shockley–Read–Hall theory. In a self-consistent way, the continuity equation is solved in order to obtain excess carriers density and also to deduce quantum efficiency, gain and responsivity as function of the wavelength. Numerical results obtained by the present approach model are in good agreement with the published experimental results for case p-PbS.     

A discrete model of adsorption with three states

A model of adsorption with recharge and allowance of the lateral interaction between molecules has been constructed within the framework of the theory of probabilistic cellular automata. Realization of this model reveals the organized behavior of the system with global synchronization of its parameters. The transition from turbulent (chaotic) to ordered regime passes through a state of local order involving the formation of leading centers (pacemakers). The appearance of self-organized behavior results from the development of intrinsic instability in the system. The process of ordering is related to the collective behavior of subsystems forming the whole system.     

Generation of amplitude squeezed states of light from phase squeezed coherent states

Abstract

We propose a scheme to generate a displaced macroscopic superposition of phase squeezed coherent states by incorporating an optical parametric oscillator (OPO) and a nonlinear Kerr medium in a Mach-Zhender interferometer configuration. We show that the phase squeezed coherent state generated by the OPO evolves into a macroscopic superposition of phase squeezed coherent states on spending a specific amount of time inside a Kerr medium. The phase space displacement is achieved by the interference of the intense reference beam with the signal in the final beam splitter of the interferometer. The noise of the reference beam contaminating the signal is prevented by making this beam splitter highly reflective. We have calculated the photon number uncertainty of the outcoming beam and have shown that it is smaller than the usual amplitude squeezed coherent state's value.