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We develop an analytical solution of fractional Schrodinger equation to explain the interaction between a two-level atom and a single electromagnetic field mode inside a cavity. Based on this solution, two different cases are discussed; the first one reflects the standard Jaynes Cummings model, while the second solution gives rise to a wave equation for a dipole interacted with a field in semi-classical sense. By controlling different parameters inside cavity, the estimation degree in terms of quantum Fisher information is investigated. The obtained results show that the precision estimation increases as the detuning decreases and number of photons inside cavity increases. Moreover robust estimation is obtained for the standard Jaynes Cummings model. To measure the amount of information, a comparative study between von Neumann entropy and quantum Fisher information show the same behavior. As a result, we conclude that quantum Fisher information may detect entanglement of the interacted atom-field system.

In this paper, we propose a model to describe the geometry of quantum correlations and entanglement through their distinct physical significance in quantum information processing and modern communications. However, geometric discord, using trace, Hilbert–Schmidt distances, and entanglement of formation, is engineered to be a well-defined non-classical correlation measure of an atomic field system. It consists of employing Jaynes–Cummings model to study the interaction between an excited atom at two levels and a single electromagnetic field mode inside an electrodynamic cavity in two cases, namely resonance and non-resonance. In fact, the dynamics of these measures depends decisively on the atom-field initial parameters where, importantly, the field parameters can be specified as control settings to implement an optimal teleportation protocol. The obtained results reveal that the behaviors of teleported geometric quantum discord and entanglement are similar to those displayed for maximum fidelity in terms of fully entanglement fraction. Therefore, since fidelity always exceeds the classical limit, one can design a quantum teleportation scheme with robust fidelity superior to any conventional communication protocol.

We propose a model of a quantum thermal refrigeration machine interacting with an external atom via an entanglement phenomenon. The machine is formed by three qubits of two-level, where each one interacts locally with its proper reservoir at different temperatures. The second qubit of the refrigerator and the external qubit are initially prepared in an entangled state. The effect of the quantum refrigerator on the entanglement of the final atomic state is studied. It is shown that the survival of the entanglement of the atomic system (Qubits 2 and 4) depends on the temperature of the second reservoir. The heat flow from the cold bath (cooling power) to the hot bath is discussed, where we prove that the refrigeration may be enhanced by the energy coming from the entangled external qubit. Indeed, it is shown that the enhancement of cooling power by increasing the degree of entanglement.

In this contribution, we investigate bidirectional quantum teleportation of single-qubit state, for the case in which qubits from the quantum channel of teleportation are distributed by typical correlated noisy channels such as bit-flip, phase-flip, depolarizing, and amplitude damping channels. Expressions of the negativity of the partially transposed density operator, fidelities of teleportation, and quantum Fisher information are evaluated, we found that all these quantities depend on factor noise and the correlation strength of the noisy channel. It is shown that the effect of the noise on entanglement, averaged fidelities of teleportation, and on quantum Fisher information could be noticeably reduced due to the existence of the noise channel correlations.

A maximum entangled atomic system consists of 2-two level atoms interacts locally with their own dissipative cavity, is discussed. We show that, the amount of the survival entanglement of the atomic system decays as the detuning parameter increases or the coupling constant decreases. A theoretical teleportation is suggest to teleport a state of one cavity initially prepared in a superposition coherent state to the second cavity is discussed, by using the atomic system as a channel. It is shown that, the efficiency of the suggested teleportation may be improved by increasing the detuning parameter or decreasing the coupling constant between the atomic systems and the cavities.

A quantum refrigerator based on anisotropic two spin-1/2 Heisenberg XYZ model in external magnetic fields with Dzyaloshinski–Moriya (DM) interaction is suggested. It consists of establishing different expressions of efficiency and thermodynamic quantities as a function of the homogeneous magnetic fields $$B_z$$ and the DM interaction ( $$D_z$$ ). A multipartite concurrence is employed as a measure of thermal entanglement in order to investigate the relationship between the entanglement and thermodynamic quantities. Many particular results related to variations in the coupling constants of the system are shown. However, the results ensure that a variation of the coupling constants has a significant impact on the results of the suggested system. All these investigations are established with respect to the conservation of the second law of thermodynamics.

In this work, we propose a simple scheme of bidirectional teleportation for transferring unknown coherent superposition states. It consists of exchanging two states by using tripartite entangled coherent states between two parts. This proposed scheme is essentially based on optical devices like beam splitters, phase shifters and photon number measurement detectors. The probability of success and the mean fidelity of quantum teleportation in the presence of quantum noise are evaluated. However, the quantum Fisher information is studied to estimate some parameters such as the weight and the phase of sent states.

The fifth generation mobile communications system actually is the most important subject in the telecommunication research. As the 5G network is way too faster, learning can be done easily between a larger number of students irrespective of their current location, to find the solutions to the different difficulty of the high frequency. A design of three different array antennas is presented in this paper. The design is done for ku band applications at 16 Ghz, the substrate height is 1.6 mm and the dielectric constant is 4.4 of flame resistant (FR4 epoxy). Simulation is done in high frequency structure simulator (HFSS) and the results are exhibited, directivity, gain, radiation patterns, 3dB beam widths and radiation efficiency are analyzed in detail. Also, an electromagnetic band gap(EBG) structure was used and analyzed with the last design which shows an increase in directivity and gain.

In the present work, an analytical fractional Schrodinger equation solution is exploited via studying the fractional evolution in time of a two interacting two-level atoms. We investigate the entanglement degree by means of concurrence of the density operator described the atom-atom interaction. Our results show that the concurrence fluctuate periodically between its maximum and minimum bounds, where in general the concurrence takes large numbers for standard fractional Schrodinger equation.

We suggest theoretically the possibility to transmit information through a decohering quantum channel employing Glauber’s coherent states. In fact, we study the dynamics of quantum correlations of two-mode entangled bipartite coherent states in the presence of the amplitude damping effect. In addition, we examine the quantum correlations based on quantum discord, which is a powerful key source in quantum information processing.

A single atomic field state is used as a quantum channel to teleport a state of two-qubit system. The possibility of estimating the teleported initial state parameters is discussed by means of quantum Fisher information. It is shown that by controlling the initial atomic field parameters, one may freeze the quantum Fisher information of the teleported parameters. Meanwhile, the teleported state keeps its local information. The sizes of the frozen areas depend on the initial state settings and the atomic field parameters. We show that the estimation degree of teleporting a single qubit is larger than that depicted for two-qubit system. Moreover, the estimation degree increases in the resonance case. It is shown that the maximum bounds of the quantum Fisher information are reached periodically. The phenomena of the sudden changes of quantum Fisher information are displayed at larger values of detuning parameters and the number of photons inside the cavity.

We propose a new construction of Bell states using modified spin coherent states and present the modified spin coherent state of the SU(2) group, along with the discussion of the states proposed.

In this contribution, we reformulated the bidirectional teleportation protocol suggested in Ref. 7, by means of Bloch vectors as well as the local operations are represented by using Pauli operators. Analytical and numerical calculations for the teleported state and Fisher information are introduced. It is shown that both quantities depend on the initial state settings of the teleported qubits and their triggers. The Fidelities and the Fisher information of the bidirectionally teleported states are maximized when the qubit and its trigger are polarized in the same direction. The minimum values are predicted if both initial qubits have different polarization or nonzero phase. The maximum values of the Fidelity and the quantum Fisher information are the same, but they are predicted at different polarization angles. We display that the multi-parameter form is much better than the single parameter form, where it satisfies the bounds of classical, entangled systems and the uncertainty principle.

A quantum heat engine (QHE) model by considering as working substance two spins (spin-1, spin-[Formula: see text]) is proposed. It consists of using different Heisenberg models with the Dzyaloshinskii-Moriya (DM) interaction in the presence of magnetic field [Formula: see text]. The proposed model contains four stroke two isochoric and two others adiabatic. A comparison of different models such that [Formula: see text], [Formula: see text] and [Formula: see text] is examined for various thermodynamics quantities, especially the efficiency [Formula: see text] and work [Formula: see text]. Finally, discussion and interpretation all results are given in the last section.

A scheme of quantum teleportation using Jaynes–Cummings model is proposed. It consists of using a partial entangled state generated from the interaction between a two-level atom and single mode of radiation field as a quantum channel. By controlling the number of photons inside cavity and detuning parameter, the dynamical evolution of quantum correlation and entanglement degree in terms of quantum discord and concurrence, respectively, in the nonresonance case are investigated. Moreover, a comparative study between the teleported entanglement, teleported quantum correlation and average fidelity shows a good similarity between their dynamical evolution. Consequently, we conclude that quantum discord may be considered as a good information source in quantum teleportation process.

The Markovianity/non-Markovianity of two different systems are discussed by means of the quantum speed limit time and quantum Fisher information. The first system is described by a central mass particle interacts locally with its surrounding particles, while the second and third models consist of a single qubit interacts with a non-detuning Lorentzian cavity and with a thermal reservoir, respectively. For the first model, the large distance between the central particle and the surrounding particles is guaranty for a fixed quantum speed limit, while the driving time plays the central role on the fixed behavior of the quantum speed limit time. Due to the stable behavior of the quantum speed limit time and the quantum Fisher information, the exchange information between the systems and their surrounding is limited. The distance between the central mass particle and its surrounding particle plays the main role on predicating the Markovianity/non-Markovianity. For the second system the driving time is an important parameter that control on the Markovianity/non-Markovianity behavior. Finally the third model proves that non-Markovianity dynamic may increase the speed and the sensitivity of the open system.

We present a scheme for implementing a quantum teleportation process using the Jaynes–Cummings model. For this, we study the interaction between an excited state of a two-level atom and a single electromagnetic field in a superposition of coherent states. The resulting entangled state may be considered as a good quantum channel for quantum teleportation protocol. By controlling the interaction field parameters inside the cavity, the average fidelity of the teleported state may be maximized. However, the weight and phase parameters in the teleported states are estimated by using quantum Fisher information. It allows one to show that the sensitivity of the teleported states fluctuates between maximum and minimum bounds for large numbers of photons. Evaluating different quantities of quantum entanglement, average fidelity, and the amount of quantum Fisher information shows that the odd coherent states are usually larger than those obtained using even coherent states.

We propose a secure quantum-network protocol using Greenberger–Horne–Zeilinger (GHZ) tripartite deformed states. Alice and Bob share a secure key by exchanging the entangled deformed states without basis reconciliation. We investigate a perfect transmission efficiency in a perfect quantum channel. The security of the protocol is ensured by the deformed and correlated tripartite states, which allows us to detect any eavesdropping easily.

A quantum key distribution protocol using an optical states based on nonorthogonal entangled pairs is investigated. It consists of sharing a similar key between the sender and the receiver by exchanging the quantum correlation of coherent states. These states are used as the support of the encoding information where affected by an amplitude damping channel. The security of the present protocol against beam splitter attack is studied as function of the information gain.

A quantum error-correcting code is established in entangled coherent states (CSs) with Markovian and non-Markovian environments. However, the dynamic behavior of these optical states is discussed in terms of quantum correlation measurements, entanglement and discord. By using the correcting codes, these correlations can be as robust as possible against environmental effects. As the number of redundant CSs increases due to the repetitive error correction, the probabilities of success also increase significantly. Based on different optical field parameters, the discord can withstand more than an entanglement. Furthermore, the behavior of quantum discord under decoherence may exhibit sudden death and sudden birth phenomena as functions of dimensionless parameters.

We study the dynamics of quantum correlation of optical coherent-state qubits affected by the environment. It consists in sending these states via a decohering quantum channel. The states used as the support of the encoding information are affected by an amplitude damping channel. The quantum discord is one of type of quantum correlations between the qubits. The discord and its dynamics of two qubits in non-Markovian environments are evaluated. © 2013 Springer Science+Business Media New York.

The entropy and Mandel function as entanglement predictable of multipartite entangled coherent states are studied. The possibility of using these states as quantum channel to perform quantum teleportation is investigated. Quantum teleportation is achieved by using both even and odd entangled coherent states in the presence of environmental noise. The effect of the field's parameters are investigated on the fidelity of the teleported state. © 2013 Springer Science+Business Media New York.

We present a secure direct communication scheme via atomic external degrees of freedom. The scheme consists of transmitting the secret message by superposition of atomic center-of-mass momentum states, quantum bit, via atomic scattering in the Bragg regime and Raman-Nath regime, respectively. The information can be coded/decoded during the transmission, without basis reconciliation, privacy amplification, and end of the communication. The security of information against any eavesdropper is ensured by the interference pattern.

We suggest a model where the influence of an environment on the atom interference is associated with a random phase. The model consists of sending a two-level state atom through two cavities, both containing a standing wave field in the Bragg regime and Raman–Nath regime, respectively. In view of this model, we can visualize the loss of interference fringes if the randomness of the phase increases, and the restoration of the pattern when it decreases, as which-path information. Then, the controllable random noise acts as a decoherence that would destroy the quantum features.

In this contribution, a generalized protocol of quantum teleportation is suggested to investigate the possibility of remotely transfer unknown multiparities entangled coherent state. A theoretical technique is introduced to generate maximum entangled coherent states which are used as quantum channels. We show that the mean photon number plays a central role on the fidelity of the transferred information. The noise parameter can be considered as a control parameter only for small values of the mean photon number.

A quantum cataloguing scheme to identify any unknown quantized cavity field state using the atom interference is proposed. The scheme consists of sending a two-level state atom through two cavities, with Bragg and Raman-Nath regimes, respectively. We inveterate the atom interference from the second cavity to achieve different interference patterns which depend on the photons statistics.

The possibility of generating entangled network via Dzyaloshinskii–Moriya interaction is investigated. The entanglement between the different nodes is quantified. This entangled network is employed to send information between different users who are members on this network. The effect of the field strength and the magnetic field parameters on the degree of entanglement of the network and the average fidelity is discussed. We show that by controlling these parameters one can maximize the average fidelity of the teleported state.

The dynamics of the maximum entangled coherent state traveling through an amplitude damping channel is investigated. For small values of the transmissivity rate, the traveling state is very fragile to this noise channel, which suffers from the phase flip error with high probability. The entanglement decays smoothly for larger values of the transmissivity rate and speedily for smaller values of this rate. As the number of modes increases, the traveling state over this noise channel quickly loses its entanglement. The odd and even states vanish at the same value of field intensity.

A quantum network is constructed via maximum entangled coherent states. The possibility of using this network to achieve communication between multi-participants is investigated. We showed that the probability of teleported unknown state successfully, depends on the size the used network. As the numbers of participants increases, the successful probability does not depend on the intensity of the field. The problem of implementing quantum teleportation protocol via a noise quantum network is discussed. We show one can send information perfectly with small values of the field intensity and larger values of the noise strength. The successful probability of this suggested protocol increases abruptly for larger values of the noise strength and gradually for small values. We show that for small size of the used quantum network, the fidelity of the teleported state decreases smoothly, while it decreases abruptly for larger size of network.