arXiv subjects

N. Metwally

Publications and source records attributed to N. Metwally.

At least 19 recordsLinked to original sources

arXiv2025

Entangling power of Anti-Jaynes-Cummings model and its efficiency to encode information in atomic system

Entangling power is crucial for quantum information processing. This study examines the Anti-Jaynes-Cummings Model (AJCM) in generating quantum correlations between two atoms interacting via the Ising model and its effect on the entangled system. The AJCM is shown to create entanglement suitable as a quantum channel for information encoding. Interaction parameters act as controls to enhance quantum correlations, increase the capacity of the final atomic state, and improve system efficiency. When the atomic system starts in a maximally entangled state, increasing interaction strength and mean photon number further boosts concurrence and channel capacity.

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arXiv2024

Teleportation two-qubit state by using two different protocols

In this contribution, two versions of teleportation protocol are considered, based on either using a single or two copies of entangled atom-field state, respectively. It is shown that, by using the first version, the fidelity of the teleported state as well as the amount of quantum Fisher information, that contains in the teleported state, are much better than using the second version. In general, one may increases the fidelity of teleported information by increasing the mean photon number and decreasing the detuning parameter. The fidelity of teleporting classical information is much better than teleporting quantum information. Moreover, teleportating classical information that initially encoded in an exited states is much better than that encodes in the ground states. However, the teleported Fisher information that initially encoded in a ground state is much larger than those initially encoded in entangled states.

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arXiv2022

Improving the bidirectional steerability between two accelerated partners via filtering process

The bidirectional steering between two accelerated partners sharing initially different classes of entangled states is discussed. Due to the decoherence, the steerability and its degree decrease either as the acceleration increases or the partners share initially a small amount of quantum correlations. The possibility of increasing the steerability is investigated by applying the filtering process. Our results show that by increasing the filtering strength, one can improve the upper bounds of the steerability and the range of acceleration at which the steerability is possible. Steering large coherent states is much better than steering less coherent ones.

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arXiv2022

Detraction of decoherence that arises from acceleration process

The possibility of detracting the decoherence due to the acceleration process of the two-qutrit system is investigated, where we examined the behaviour of the relative entropy and the non-local information. For this purpose, the accelerated subsystems are allowed to pass through local or global noisy channels. It is shown that, the detraction potential depends on the type of the used noisy channel, local or global, and the initial settings of the accelerated qutrit systems, whether it is prepared in free or bound entangled intervals. The improving rate that depicted for systems prepared in the free entangled intervals is much better than those prepared in the bound entangled interval. The maximum bounds of the non-local information in the presence of the amplitude damping channels are larger than those passes in the dephasing channel.

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arXiv2022

Decoherence and quantum steering of accelerated qubit-qutrit system

The bidirectional steerability between different-size subsystems is discussed for a single parameter accelerated qubit-qutrit system. The decoherence due to the mixing and acceleration parameters is investigated, where for the total system and the qutrit, it increases as the mixing parameter increases, while it decreases for the qubit. The non-classical correlations are quantified by using the local quantum uncertainty, where it increases at large values of the acceleration parameter. The possibility that each subsystem steers each other is studied, where the behavior of the steering inequality predicts that the qubit has a large ability to steer the qutrit. The degree of steerability decays gradually when the qubit is accelerated. However, it decays suddenly when the qutrit or both subsystems are accelerated. The degree of steerability is shown for the qutrit/qubit vanishes at small/large values of the acceleration. The difference between the degrees of steerability depends on the initial state settings and the size of the accelerated subsystem.

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arXiv2022

Exchanging quantum correlations and non-local information between three qubit-syatem

The possibility of exchanging the quantum correlations and the non-local information between three qubits interact directly or indirectly via Dzyaloshinskii-Moriya (DM)is discussed. The initial state settings and the interaction strength represent control parameters on the exchanging phenomena. The non-local information that encoded on the different partitions doesn't exceed the initial one. It is shown that, the ability of DM interaction to generate entanglement is larger than that displayed for the dipole interaction. The possibility of maximizing the quantum correlations between the three qubits increases as one increase the strength of interaction and starting with large initial quantum correlations. The long-lived quantum correlations could be achieved by controlling the strength of the dipole interaction.

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arXiv2021

The orthogonality speed of two-qubit state interacts locally with spin chain in the presence of Dzyaloshinsky-Moriya interaction

The orthogonality time is examined for different initial states settings interacting locally with different types of spin interaction: $XX$, Ising and anisotropic models. It is shown that, the number of orthogonality increases, and consequently the time of orthogonality decreases as the environment qubits increase. The shortest time of orthogonality is displayed for the $XX$ chain model, while the largest time is shown for the Ising model. The external field increases the numbers of orthogonality, while Dzyaloshinsky-Moriya interaction decreases the time of orthogonality. The initial state settings together with the external field has a significant effect on decreasing/increasing the time of orthogonality

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arXiv2020

Generating multi-hops entangled network via spin Dipolar interaction

The possibility of generating a multi-hops network between different entangled nodes (qubits) via spin Dipolar interaction is examined. The negativity, tangle and the non-local coherent advantage are used as quantifiers of the generated quantum correlations. The phenomena of the sudden death/birth is displayed for the entangled two nodes, while the sudden changes phenomena (increasing/ decreasing) is depicted for all entangled three nodes. The amount of correlations between the different nodes depend on the initial network settings, where the largest amount is predicted if the network is initially conducted via maximum entangled nodes. The generated quantum correlations between each three nodes are more robust than those generated between two nodes. For the generated entangled two nodes, the direction of the interaction and its strength have a remarkable effect on the correlation behavior, while they has a slightly effect on the correlation of the three nodes.

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arXiv2020

Restrain the losses of the entanglement and the non-local advantage of quantum coherence for accelerated quantum systems

We examined the possibility of recovering the losses of entanglement and the non-local advantage by using the local symmetric operations. The improvement efficiency may be increased by applying the symmetric operations on both qubits. The recovering process of both phenomenon is exhibited clearly when only one qubit is accelerated and the symmetric operations is applied on both qubits. It is shown that, for large acceleration, the non-local coherent advantage may be re-birthed by using these symmetric operations.

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arXiv2020

Wigner distribution function of atomic system interacts locally with a deformed cavity

Wigner distribution function of atomic system interacts locally with a deformed cavity is discussed. It is shown that, the deformed cavity has a destructive effect on the Wigner distribution function, where it decreases as one increases the deformation strength. The upper and lower bounds of the Wigner distribution function depends on the initial state settings of atomic system (entangled/product), the initial values of the dipole-dipole interaction's and detuning parameters, and the external distribution weight and the phase angles. The possibility of suppressing the decay induced by the deformed cavity may be increased by increasing the dipole's strength or the detuning parameter. We show that the distribution angles may be considered as a control external parameters, that maximize/ minimize the Wigner distribution function. This means that by controlling on the distribution angles, one can increase the possibility of suppressing the decoherence induced by the deformed cavity.

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arXiv2020

Steering information in quantum network

In this contribution, we investigate the possibility that one member of a quantum network can steer the information that encoded in the state of other member. It is assumed that, these members have a direct or indirect connections. We show that, the steerability increases at small values of the channel' strength. Although, the degree of entanglement between the direct interacted nodes is smaller than that displayed for the non-interacted nodes, the possibilities of steering a member of the direct interacted nodes and the non-direct nodes are almost similar.

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arXiv2019

Fisher information of accelerated two-qubit system in the presence of the color and white noise channels

In this manuscript, we investigate the effect of the white and color noise on a accelerated two-qubit system, where different initial state setting are considered. The behavior of the survival amount of entanglement is quantified for this accelerated system by means of the concurrence. We show that, the color noise enhances the generated entanglement between the two particles even for small values of the initial purity of the accelerated state. However, the larger values of the white noise strength improve the generated entanglement. The initial parameters that describe this system are estimated by using Fisher information, where two forms are considered, namely by using a single and two-qubit forms. It is shown that, by using the two-qubit form, the estimation degree of these parameters is larger than that displayed by using a single-qubit form.

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arXiv2019

Wigner function of noisy accelerated two-qubit system

In this manuscript, the behavior of the Wigner function of accelerated and non-accelerated two qubit system passing through different noisy channels is discussed. The decoherence of the initial quantum correlation due to the noisy channels and the acceleration process is investigated by means of Wigner function. The negative (positive) behavior of the Wigner function predicts the gain of the quantum (classical) correlations. Based on the upper and lower bounds of the Wigner function, the entangled initial state loses its quantum correlation due the acceleration process and the strengths of the noisy channels. However, by controlling the distribution angles, the decoherence of these quantum correlation may be suppressed. For accelerated state, the robustness of the quantum correlations contained in the initial state appears in different ranges of the distribution angles depending on the noisy type. For the bit phase flip and the phase flip channels, the robustness of the quantum correlations is shown at any acceleration and large range of distribution angles. However, the fragility of the quantum correlation is depicted for large values for strength of the bit flip channel. Different profiles of the Wigner function are exhibited for the quantum and classical correlations, cup, lune, hemisphere.

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arXiv2019

Wigner function of accelerated and non-accelerated Greenberger Horne Zeilinger State

The Wigner function's behavior of accelerated and non-accelerated Greenberger Horne Zeilinger (GHZ) state is discussed. For the non-accelerated GHZ state, the minimum/maximum peaks of the Wigner function depends on the distribution's angles, where they are displayed regularly at fixed values of the distribution's angles. We show that, for the accelerated GHZ state, the minimum bounds increases as the acceleration increases. The increasing rate depends on the number of accelerated qubits. Due to the positivity/ negativity behavior of the Wigner function, one can use it as an indicators of the presences of the classical/quantum correlations, respectively. The maximum bounds of the quantum and the classical correlations depend on the purity of the initial GHZ state. The classical correlation that depicted by the behavior of Wigner function independent of the acceleration, but depends on the degree of its purity.

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arXiv2018

Maximizing the encoded information via freezing the estimated parameters of a pulsed driven qubit

We use a rectangular pulse to freeze the possibility of estimating the coherent parameters ($θ,ϕ$) of a single qubit and the encoded information. It is shown that, as the possibility of estimating the parameters increases, the amount of encoded information decreases. The pulse strength and the detuning between the qubit and the pulse have a different effect on the estimation degree and the encoded information. We show that if the weight parameter, $θ$ is estimated, the encoded information depends on the initial state settings. Meanwhile, the encoded information doesn't depend on the estimated phase parameter,$ϕ$. These results may be useful in the context of quantum cryptography, teleportation and secure communication.

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arXiv2018

Frozen accelerated information via local operations

In this contribution, we introduce a technique to freeze the parameters which describe the accelerated states between two users to be used in the context of quantum cryptography and quantum teleportation. It is assumed that, the two users share different dimension sizes of particles, where we consider a qubit-qutrit system. This technique depends on local operations, where it is allowed that each particle interacts locally with a noisy phase channel. We show that, the possibility of freezing the information of quantum channel between the users depends on the initial state setting parameters, the initial acceleration parameter strength of the phase channel. It is shown that, one may increase the possibility of freezing the estimation degree of the parameters if only the larger dimension system or both particles pass through the noisy phase channel. Moreover, at small values of initial acceleration and large values of the channel strength, the size of freezing estimation areas increases. The results may be helpful in the context of quantum teleportation and quantum coding.

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arXiv2017

Fisher information of a single qubit interacts with a spin-qubit in the presence of a magnetic field

In this contribution, quantum Fisher information is utilized to estimate the parameters of a central qubit interacting with a single-spin qubit. The effect of the longitudinal, transverse and the rotating strengths of the magnetic field on the estimation degree is discussed. It is shown that, in the resonance case, the number of peaks and consequently the size of the estimation regions increase as the rotating magnetic field strength increases. The precision estimation of the central qubit parameters depends on the initial state settings of the central and the spin- qubit, either encode classical or quantum information. It is displayed that, the upper bounds of the estimation degree are large if the two qubits encode classical information. In the non-resonance case, the estimation degree depends on which of the longitudinal/transverse strength is larger. The coupling constant between the central qubit and the spin- qubit has a different effect on the estimation degree of the weight and the phase parameters, where the possibility of estimating the weight parameter decreases as the coupling constant increases, while it increases for the phase parameter. For large number of spin-particles, namely, we have a spin-bath particles, the upper bounds of the Fisher information with respect to the weight parameter of the central qubit decreases as the number of the spin particle increases. As the interaction time increases, the upper bounds appear at different initial values of the weight parameter.

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arXiv2017

Estimation of pulsed driven qubit parameters via quantum Fisher information

We estimate the initial weight and phase parameters ($θ, ϕ)$ of a single qubit system initially prepared in the coherent state $\ket{θ,ϕ}$ and interacts with three different shape of pulses; rectangular, exponential, and $sin^2$-pulses. In general, we show that the estimation degree of the weight parameter depends on the pulse shape and the initial phase angle, $(ϕ)$. For the rectangular pulse case, increasing the estimating rate of the weight parameter via the Fisher information function $(\mathcal{F}_θ)$ is possible with small values of the atomic detuning parameter and larger values of the pulse strength. Fisher information $(\mathcal{F}_ϕ)$ increases suddenly at resonant case to reach its maximum value if the initial phase $ϕ=π/2$ and consequently one may estimate the phase parameter with high degree of precision. If the initial system is coded with classical information, the upper bounds of Fisher information for resonant and non-resonant cases are much larger and consequently one may estimate the pahse parameter with high degree of estimation. Similarly as the detuning increases the Fisher information decreases and therefore the possibility of estimating the phase parameter decreases. For exponential, and $sin^2$-pulses the Fisher information is maximum ($\mathcal{F}_{θ,ϕ}=1$) and consequently one can always estimate the weight and the phase parameters $(θ,ϕ)$ with high degree of precision.

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