Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Journal of Nanchang University

Entanglement properties in two superconducting charge qubits system interacting with a squeezed coherent state

Liao Qing-hon

Published Jan 1, 2013• 0 citations
OpenAlex

Abstract

The dynamics of entanglement of two superconducting charge qubit system interacting with a squeezed coherent state were examined by means of linear entropy. The influence of the relative phase of the two qubits' levels and squeezing parameter on the time evolution of linear entropy was discussed. The results showed that the linear entropy almost tends to zero at half the revival time when the two qubits were initially in the maximally entangled state. It was also showed that a greater number of oscillations of the linear entropy were observed with the increasing of squeezing parameter and the sustainment time of the maximum entropy was increased. There was no change in the maximum value of the linear entropy. Moreover,the relative phase of the two qubits' levels decreased the degree of entanglement between the two qubits and the field.

Related papers

Linear Entropy and Entanglement in Two-Charge-Qubit Circuits

Liao Qing-Hong, Fang Guang-Yu, Wang Yue-Yuan +2 more

We consider a model that contains two coupled superconducting charge qubits by sharing a large Josephson junction. We examine the dynamical properties of the linear entropy of two qubits and the probability of both qubits being in an excited state. The results show that the initial mean photon number, the initial phase of the field and the relative phase of the two qubits' levels play an important role in the evolution of the linear entropy of the two qubits and the probability.

Chinese Physics Letters•Jul 1, 2010•4 citations

Quantum entanglement in a system of squeezed coherent state light field interacting with two entangled atoms

Caihua Zhang, Sachuerfu, Gerile

The quantum entanglement of two entangled atoms interacting with the squeezed coherent state is studied by means of full quantum theory. The influences of coherent amplitude factor, squeezing factor, ratio of two coupling coefficients on the entanglement property are discussed. The results show that two atoms entanglement evolution property is opposed to atom-field entanglement evolution property when the coherent amplitude factor was zero or small. The interaction of the atoms and field weakens the entanglement degree of atom-atom. With increasing coherent amplitude factor or decreasing squeezing factor of light, the time of two atoms staying in the steady entangled state becomes longer. The increase of the coherent amplitude factor or the decrease of squeezing factor of light lead to the increase of atom-atom entanglement degree while the decrease of atoms-field entanglement degree. Moreover, the two-atom quantum state stays in the maximum entangled state when the atomic dipole-dipole coupling coefficient is large enough.

Chinese Journal of Quantum Electronics•Jan 1, 2010•0 citations

Entanglement and Entropy Squeezing for Moving Two Two-Level Atoms Interaction with a Radiation Field

S. Abdel‐Khalek, Eied Mahmoud Khalil, Beida Alsubei +3 more

In this paper, we analyzed squeezing in the information entropy, quantum state fidelity, and qubit-qubit entanglement in a time-dependent system. The proposed model consists of two qubits that interact with a two-mode electromagnetic field under the dissipation effect. An analytical solution is calculated by considering the constants for the equations of motion. The effect of the general form of the time-dependent for qubit-field coupling and the dissipation term on the temporal behavior of the qubit-qubit entanglement, quantum state fidelity, entropy, and variance squeezing are examined. It is shown that the intervals of entanglement caused more squeezing for the case of considering the time-dependent parameters. Additionally, the entanglement between the qubits became more substantial for the case of time dependence. Fidelity and negativity rapidly reached the minimum values by increasing the effect of the dissipation parameter. Moreover, the amount of variance squeezing and the amplitude of the oscillations decreased considerably when the time dependence increased, but the fluctuations increased substantially. We show the relation between entropy and variance squeezing in the presence and absence of the dissipation parameter during the interaction period. This result enables new parameters to control the degree of entanglement and squeezing, especially in quantum communication.

Computers, materials & continua/Computers, materials & continua (Print)•Jan 1, 2021•3 citations

Evolution of Field Entropy in a System of Squeezed Coherent State Light Field Interacting with Two Moving Entangled Atoms

Zhang Caihua

The field entropy evolution in a system which is composed of two moving entangled atoms interacting with the squeezed coherent state is studied by means of the full quantum theory.The influences of the coherent amplitude factor,the squeezing factor,the atomic motion and the field-model structure parameter on the field entropy are discussed.The result shows that the atomic motion leads to the periodic evolution of the field entropy.An increase of coherent amplitude factor weaken the degree of entanglement between the atoms and the light field.However,an increase of squeezing factor of light strengthen the degree of entanglement between the atoms and the light field.With increasing atomic speed or field-model structure parameter,the evolution period of the field entropy becomes shorter,and the degree of entanglement between field and moving atoms becomes smaller.

Acta Sinica Quantum Optica•Jan 1, 2009•0 citations

Control of the Entanglement between Two Josephson Charge Qubits

Qinghong Liao, Guangyu Fang, Jicheng Wang +1 more

We consider a model which consists of two coupled superconducting charge qubits by sharing a large Josephson junction. The time evolution of entanglement between two Josephson charge qubits is investigated by employing the concurrence. We examine the influence of the initial mean photon number, the relative phase and the amplitude of the two qubits on the time evolution of entanglement. The results show that the initial mean photon number, the relative phase and the amplitude of the two qubits play an important role in the evolution of entanglement.

Chinese Physics Letters•Jun 1, 2011•14 citations

The Study of Dynamics Properties of Entanglement of Two Interacting Atoms Coupled to Markovion and Non-Markovion Environment

Liao Qing-hon

The entanglement dynamics of two interacting qubits under the influence of Markovian environment and non-Markovian environment was examined by making use of the linear entropy.The effect of the strength of the dipole-dipole interaction and the detuning between the transition frequency of the atom and the center frequency of the reservoir on the time evolution of entanglement was discussed.It is shown that linear entropy decreases with the increase of the strength of the dipole-dipole interaction and the detuning between the transition frequency of the atom and the center frequency of the reservoir.Linear entropy tends to steady state within a short time in the Markovian environment,but in the nonMarkovian environment linear entropy shows oscillatory behavior with the time evolution.

ACTA PHOTONICA SINICA•Jan 1, 2015•0 citations
The dynamics of entanglement of two superconducting charge qubit system interacting with a squeezed coherent state were examined by means of linear entropy. The influence of the relative phase of the two qubits' levels and squeezing parameter on the time evolution of linear entropy was discussed. The results showed that the linear entropy almost tends to zero at half the revival time when the two qubits were initially in the maximally entangled state. It was also showed that a greater number of oscillations of the linear entropy were observed with the increasing of squeezing parameter and the sustainment time of the maximum entropy was increased. There was no change in the maximum value of the linear entropy. Moreover,the relative phase of the two qubits' levels decreased the degree of entanglement between the two qubits and the field.
The quantum entanglement of two entangled atoms interacting with the squeezed coherent state is studied by means of full quantum theory. The influences of coherent amplitude factor, squeezing factor, ratio of two coupling coefficients on the entanglement property are discussed. The results show that two atoms entanglement evolution property is opposed to atom-field entanglement evolution property when the coherent amplitude factor was zero or small. The interaction of the atoms and field weakens the entanglement degree of atom-atom. With increasing coherent amplitude factor or decreasing squeezing factor of light, the time of two atoms staying in the steady entangled state becomes longer. The increase of the coherent amplitude factor or the decrease of squeezing factor of light lead to the increase of atom-atom entanglement degree while the decrease of atoms-field entanglement degree. Moreover, the two-atom quantum state stays in the maximum entangled state when the atomic dipole-dipole coupling coefficient is large enough.
In this paper, we analyzed squeezing in the information entropy, quantum state fidelity, and qubit-qubit entanglement in a time-dependent system. The proposed model consists of two qubits that interact with a two-mode electromagnetic field under the dissipation effect. An analytical solution is calculated by considering the constants for the equations of motion. The effect of the general form of the time-dependent for qubit-field coupling and the dissipation term on the temporal behavior of the qubit-qubit entanglement, quantum state fidelity, entropy, and variance squeezing are examined. It is shown that the intervals of entanglement caused more squeezing for the case of considering the time-dependent parameters. Additionally, the entanglement between the qubits became more substantial for the case of time dependence. Fidelity and negativity rapidly reached the minimum values by increasing the effect of the dissipation parameter. Moreover, the amount of variance squeezing and the amplitude of the oscillations decreased considerably when the time dependence increased, but the fluctuations increased substantially. We show the relation between entropy and variance squeezing in the presence and absence of the dissipation parameter during the interaction period. This result enables new parameters to control the degree of entanglement and squeezing, especially in quantum communication.
The field entropy evolution in a system which is composed of two moving entangled atoms interacting with the squeezed coherent state is studied by means of the full quantum theory.The influences of the coherent amplitude factor,the squeezing factor,the atomic motion and the field-model structure parameter on the field entropy are discussed.The result shows that the atomic motion leads to the periodic evolution of the field entropy.An increase of coherent amplitude factor weaken the degree of entanglement between the atoms and the light field.However,an increase of squeezing factor of light strengthen the degree of entanglement between the atoms and the light field.With increasing atomic speed or field-model structure parameter,the evolution period of the field entropy becomes shorter,and the degree of entanglement between field and moving atoms becomes smaller.
We consider a model which consists of two coupled superconducting charge qubits by sharing a large Josephson junction. The time evolution of entanglement between two Josephson charge qubits is investigated by employing the concurrence. We examine the influence of the initial mean photon number, the relative phase and the amplitude of the two qubits on the time evolution of entanglement. The results show that the initial mean photon number, the relative phase and the amplitude of the two qubits play an important role in the evolution of entanglement.
The entanglement dynamics of two interacting qubits under the influence of Markovian environment and non-Markovian environment was examined by making use of the linear entropy.The effect of the strength of the dipole-dipole interaction and the detuning between the transition frequency of the atom and the center frequency of the reservoir on the time evolution of entanglement was discussed.It is shown that linear entropy decreases with the increase of the strength of the dipole-dipole interaction and the detuning between the transition frequency of the atom and the center frequency of the reservoir.Linear entropy tends to steady state within a short time in the Markovian environment,but in the nonMarkovian environment linear entropy shows oscillatory behavior with the time evolution.