Search

This study investigates the quantum heat correlations associated with the quantum Otto machine, considering the discrete sides of the Lipkin-Meshkov-Glick model as the working medium in the presence of a magnetic field and a symmetric cross interaction. The eigenenergy and occupation probabilities of two-sided and three-sided spin interactions are determined at thermal equilibrium. The results reveal symmetrical heat correlations around the coupling of the symmetric cross interaction, regardless of whether the working medium adopts anisotropic XY, Ising model, or mixed ferromagnetism. The work done by two or three sides of the mixed ferromagnetic working substance exhibits symmetry but with different maximum bounds. Furthermore, the efficiency of the two-sided mixed ferromagnetism model improves as the exchange parameter increases, while the maximum efficiency of the anisotropic XY model is lower compared to the efficiency of the Ising model and mixed ferromagnetism. It is also highlighted that a quantum heat engine or refrigerator can be generated by controlling the system's anisotropy parameter using a three-sided spin interaction. [ABSTRACT FROM AUTHOR]

This paper investigates the entanglement dynamics of a two‐qubit system in the presence of n‐sequential sin2$ \sin ^2$‐pulse shape. The study explores entanglement under two scenarios: when the system is completely isolated from the environment and when it interacts with one of the surrounding environments, namely the thermal environment and the common dephasing environment. The authors quantify entanglement through concurrence while systematically examining the effects of initial state preparation, qubit coupling strength, laser‐qubit interaction intensity, pulse sequences, and decohering environments. The results highlight that the entanglement of the two‐qubit system strongly depends on the initial state. Increasing the coupling strength between the qubits and the n‐sequential pulse enhances the maximum values of entanglement. Conversely, augmenting the laser‐qubits coupling or introducing the influence of the environment diminishes the entanglement. [ABSTRACT FROM AUTHOR]

We explain how a surface optical vortex can be created when a Bessel beam is totally reflected internally at the planar surface of a dielectric on which a metallic sheet has been deposited. A two-dimensional patterning on the surface, the strongly localized intensity distribution decays with distance vertical to the surface. The characteristics of this surface optical vortex depend on the incident beam parameters and the dielectric mismatch of the media. [ABSTRACT FROM AUTHOR]

We are concerned with an analytic separation approach of the optical Bloch equations in the case of the two-level atom interacting with a classical light. The conditions that permit a complete separation of these equations are extracted in a natural manner and the exact solutions are obtained. A theoretical comparison with Torrey method is given. In this context, we find that the transient regime, valid from the instant of the application of the laser on atom, is significant for the evolution of forces and the dynamics before the steady-state regime will be reached. The case of Eu3 + ion moving in plane-light wave and standing-wave is treated with some details. The implications of the results for operating atoms and ions using laser light are discussed. [ABSTRACT FROM AUTHOR]

An extended analytic approach is considered for optical Bloch equations in the two level atom interacting with laser light. The separation approach of coupled differential equations is always possible with a sequence of special transformation into the Riccati nonlinear differential equation. The conditions that permit an exact solutions of three coupled system are extracted in a natural manner. The case of sodium atom moving along the axis of a monochromatic wave is treated in some details including a discussion on the radiation pressure forces exerted by laser light in the transient regime. [ABSTRACT FROM AUTHOR]

This paper investigates the impact of dipole interactions and the initial quantum state configurations within a quantum system on teleported quantum correlations involving a pair of qubits embedded in a single-mode field. The analysis encompasses an exploration of non-separability, steerability, non-locality, and steered coherence of the teleported state, considering different initial Bell states for the two-qubit channel. The initial atomic setting state primarily influences the teleported quantum correlations. The study highlights that dipole interaction exert a substantial effect on both the maximum and minimum values of quantum correlations. Furthermore, increasing this interaction demonstrates the potential to enhance control over the decay of correlations induced by the detuning parameter. [ABSTRACT FROM AUTHOR]

The interaction of a 2-level atom with a time-dependent cavity field (two-photon non-degenerate transitions) in the parametric amplifier-type is considered. Using the integrability conditions, taking into account the phase and coupling, a general solution of the model is obtained through the Schrödinger equation. The effects of the functional dependence of the coupling and the initial state of the 2-level atom on atomic inversion, the degree of entanglement, entropy squeezing are investigated. It is shown that the acceleration term plays an important role in controlling the functions behavior of the considered quantities. [ABSTRACT FROM AUTHOR]

In this article, we study the entropy squeezing and the nonlocal correlation between a nonlinear quantum system initially in the BGS (Barut-Girardello state) and 2LA (two-level atom). The numerical solution is used for solving the differential equations to obtain the density matrix. The relation between the atomic inversion, nonlocal correlation measured by the negativity and entropy are discussed. The effective of classical field and damping on the dynamical properties of the entanglement and entropy squeezing is examined. The results are shown that a high amount of classical field due to the entanglement reached to minimum values. Finally the proposed quantum system being more resistant to the damping effect in the absence of classical field than the presence of classical field. [ABSTRACT FROM AUTHOR]

We discuss the effect of damping on a quantum system specifically described by the su(1, 1) Lie algebra and interacting with a two-level atom in the presence of external classical su(1, 1) terms. We obtain the numerical solution of the associated differential equations and discuss in detail several statistical aspects, atomic inversion, squeezing phenomena, and negativity. In addition, we analyze the effect of the decay parameter and the external classical su(1, 1) terms on the population inversion and purity. Finally, we examine the entropy squeezing and the degree of entanglement for some values of the damping and detuning parameters. [ABSTRACT FROM AUTHOR]