理论物理通讯：英文版

Control and Transfer of Entanglement between Two Atoms Driven by Classical Fields under Dressed-State Representation

廖庆洪, Zhang Qi Zhang Qi, 许娟, 鄢秋荣, 刘晔, 陈桉

Published Jan 1, 2016• 0 citations

Abstract

We have studied the dynamics and transfer of the entanglement of the two identical atoms simultaneously interacting with vacuum field by employing the dressed-state representation. The two atoms are driven by classical fields. The influence of the initial entanglement degree of two atoms, the coupling strength between the atom and the classical field and the detuning between the atomic transition frequency and the frequency of classical field on the entanglement and atomic linear entropy is discussed. The initial entanglement of the two atoms can be transferred into the entanglement between the atom and cavity field when the dissipation is neglected. The maximally entangled state between the atoms and cavity field can be obtained under some certain conditions. The time of disentanglement of two atoms can be controlled and manipulated by adjusting the detuning and classical driving fields. Moreover, the larger the cavity decay rate is, the more quickly the entanglement of the two atoms decays.

Related papers

Control and Transfer of Entanglement between Two Atoms Driven by Classical Fields under Dressed-State Representation*

Qinghong Liao, Qi Zhang, Juan Xu +3 more

Abstract We have studied the dynamics and transfer of the entanglement of the two identical atoms simultaneously interacting with vacuum field by employing the dressed-state representation. The two atoms are driven by classical fields. The influence of the initial entanglement degree of two atoms, the coupling strength between the atom and the classical field and the detuning between the atomic transition frequency and the frequency of classical field on the entanglement and atomic linear entropy is discussed. The initial entanglement of the two atoms can be transferred into the entanglement between the atom and cavity field when the dissipation is neglected. The maximally entangled state between the atoms and cavity field can be obtained under some certain conditions. The time of disentanglement of two atoms can be controlled and manipulated by adjusting the detuning and classical driving fields. Moreover, the larger the cavity decay rate is, the more quickly the entanglement of the two atoms decays.

Communications in Theoretical PhysicsJun 1, 20166 citations

Atom–atom entanglement dynamics enhancement via classically driven atoms coupled to a non-resonance single mode cavity field filled with nonlinear Kerr media

M. S. Ateto

Entanglement dynamics of two identical non-interacting atoms (qubits) coupled individually with simultaneous classical and quantum fields are studied. The cavity field is filled with a nonlinear Kerr medium and initially prepared in a coherent state. The atoms are initially set up as a Bell-like pure state (BS). We present an approach for diagonalization of time-dependent nonlinear Hamiltonian of the system exactly. Connection between the change in the degree of entanglement and tomography of field state in phase space are also illustrated and interpreted. We demonstrate the possibility of atom–atom (qubit–qubit) entanglement optimization by suitably choosing initial interaction settings. Overall, we show that both classical driving amplitude and detuning as well as Kerr media and initial atomic states acts as the control parameters for the qubit–qubit entanglement. By adjusting of these parameters, accurately, entanglement can be enhanced noticeably and high degree of steady periodical entanglement can be generated. Moreover, starting with initial atomic BSs in presence of classical driving suppresses coherences randomness and considerably accompanied with (for specific values of detuning) slight decrease in their amplitudes. Furthermore, the addition of cross Kerr term suppresses degree of entanglement noticeably, where entanglement creation and enhancement could just be possible if cross Kerr effect is moved out from interaction. Our present approach promises the great advantage of being suitable for large quantum systems of various kinds of nonlinearities.

International Journal of Quantum InformationAug 1, 20157 citations

Classical-driving-assisted coherence dynamics and its conservation

Gao De-ying, Qiang Gao, Yun‐Jie Xia

We investigate the quantum coherence and quantum entanglement dynamics of a classical driven single atom coupled to a single-mode cavity. It is shown that the transformation between the atomic coherence and the atom-field entanglement exists, and can be improved by adjusting the classical driving field. The joint evolution of two identical single-body systems is also studied. The results show the quantum coherence transfers among composite subsystems, and the coherence conservation of composite subsystems is obtained. Moreover, the classical driving field can be used to suppress the decay of the coherence and entanglement, owing to considering the leaky cavity. The non-Markovian dynamics of the system is also discussed finally.

Chinese Physics BJun 1, 20181 citation

Enhancing entanglement generation of two atoms in a cavity with white noise using classical driving fields

张建松 Jiansong Zhang, 陈爱喜 Aixi Chen

We investigate the entanglement dynamics of a quantum system consisting of two two-level atoms in a cavity with classical driving fields in the presence of white noise.The cavity is initially prepared in the vacuum state.Generally, the entanglement of two atoms decreases with the intensity of the thermal fields and the coupling strength of the two-level atoms to the thermal fields.However, we find that the entanglement of the quantum system can be enhanced by adjusting the frequency and the strength of the classical driving fields in the presence of white noise.

Chinese Optics LettersJan 1, 20110 citations

Control of two-atom entanglement with two thermal fields in coupled cavities

Li-Tuo Shen, Zhen‐Biao Yang, Huai‐Zhi Wu +2 more

The dynamical evolution of a quantum system composed of two coupled cavities, each containing a two-level atom and a single-mode thermal field, is investigated under different conditions. The entanglement between the two atoms is controlled by the hopping strength and the detuning between the atomic transition and the cavities. We find that when the atomic transition is far off-resonant with both the eigenmodes of the coupled-cavity system, the maximally entangled state for the two atoms can be generated with the initial state in which one atom is in the ground state and the other is in the excited state. When both the two atoms are initially in the excited state, the entanglement exhibits periodical sudden birth and death. By choosing appropriate parameter values, the initial maximal entanglement of the two atoms can be frozen. The relation between the concurrence and the cooperative parameter is calculated.

arXiv:1207.3125Journal of the Optical Society of America BAug 9, 201217 citations

Entanglement dynamics of two qubits driven by classical laser field

Xiao Qing-sheng

The entanglement dynamics of two two-level atoms which are respectively trapped in two independent dissipative single-mode cavities and strongly driven by the classical fields is investigated analytically utilizing the super operator method.It is found that the entanglement is not related to the initial value of the cavity coherent states.The driving field enhances the entanglement sudden death for small dissipation of the cavity,while it protects the entanglement from sudden death for large dissipation in the presence of strong driving field.These results show that even in the bad cavity(with large decay rate),the entanglement can be free from sudden death with the assistance of classical driving field.

Chinese Journal of Quantum ElectronicsJan 1, 20100 citations