Quantum discord between two moving two-level atoms

Open Physics ◽  
2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Yao-Hua Hu ◽  
Mao-Fa Fang

AbstractConsidering a double JC model, this paper investigates the quantum discord dynamics of two isolated moving two-level atoms each interacting with a single-mode thermal cavity field, and studies the effect of the atomic motion and the field-mode structure on quantumdiscord. The results show that, on the one hand the quantum discord evolves periodically with time and the periods are affected by the atomic motion and the field-mode structure; on the other hand, the quantum discord still can capture the quantum correlation between the two atoms when the entanglement is zero. It is interesting to note that the quantum discord can be effectively preserved by controlling the field-mode structure parameter

2003 ◽  
Vol 17 (30) ◽  
pp. 5795-5810 ◽  
Author(s):  
R. A. ZAIT

We study the dynamics and quantum characteristics of a single two-level atom interacting with a single mode cavity field undergoing a multi-photon processes in the presence of a nonlinear Kerr-like medium. The wavefunctions of the multi-photon system are obtained when the atom starts in the excited and in the ground state. The atomic inversion, the squeezing of the radiation field and the quasiprobability distribution Q-function of the field are discussed. Numerical results for these characteristics are presented when the atom starts in the excited state and the field mode in a coherent state. The influence of the presence and absence of the number operator and the Kerr medium for the one- and two-photon processes on the evolution of these characteristics are analyzed.


2012 ◽  
Vol 10 (01) ◽  
pp. 1250007 ◽  
Author(s):  
NOUR ZIDAN ◽  
S. ABDEL-KHALEK ◽  
M. ABDEL-ATY

In this paper, we investigate the geometric phase of the field interacting with a moving four-level atom in the presence of Kerr medium. The results show that the atomic motion, the field-mode structure and Kerr medium play important roles in the evolution of the system dynamics. As illustration, we examine the behavior of the geometric phase and entanglement with experimentally accessible parameters. Some new aspects are observed and discussed.


1992 ◽  
Vol 06 (21) ◽  
pp. 3539-3550 ◽  
Author(s):  
AMITABH JOSHI ◽  
SURESH V. LAWANDE

We study the squeezing and the quasiprobability distribution Q-function for an extended two-photon Jaynes-Cummings model (JCM) that includes atomic motion and the field mode structure. A comparative study of this model with respect to the standard model (in which the atom is at rest) has been presented here to isolate the effect of limited atom-radiation interaction time.


2020 ◽  
Vol 34 (10) ◽  
pp. 2050093
Author(s):  
K. El Anouz ◽  
I. El Aouadi ◽  
A. El Allati ◽  
T. Mourabit

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.


2003 ◽  
Vol 02 (01n02) ◽  
pp. 49-63 ◽  
Author(s):  
Mahmoud Abdel-Aty ◽  
Tarek M. El-Shahat ◽  
Abdel-Shafy F. Obada

We present a detailed theory of a general formalism of a nonlinear JC-model. In particular we explicitly take into account forms of nonlinearities of both the field and the intensity-dependent atom-field coupling and study the properties of the fluorescence spectrum in this system. The exact solution for time-dependence of the atom-field system is obtained, by means of which we analyze the analytic form of the fluorescence spectrum produced by an atom in an ideal cavity using the transitions among the dressed states of the system. We investigate the influences of the nonlinearities on the fluorescence spectrum, for initial squeezed, thermal and coherent states. It is shown that features of the fluorescence spectrum are significantly influenced by the kinds of nonlinearities of the single-mode field.


2020 ◽  
Vol 7 (1) ◽  
pp. 4
Author(s):  
Hristo Tonchev

This paper describes two cases of interaction between a quantized electromagnetic field and two different XY spin molecules; one with spins ½, and the other with spins 1. Both interact with a quantized electromagnetic field, with one of the spins in the chain interacting with the electromagnetic field. The interaction between the field mode and the spin chain with spins 1 is described by the one- and two-photon Jaynes-Cummings model (JC model). On the other hand, the interaction between the spins ½ and the electromagnetic field is described only by the one-photon Jaynes-Cummings model. Analytical and numerical calculations were made for the case of a different number of photons in the field mode, a different number of spins, and a different position of spin, interacting with the electromagnetic field. The invariant and block structures of such a chain are shown with a comparison made between the evolution of the magnetic moment and the number of photons in both cases.


2006 ◽  
Vol 04 (05) ◽  
pp. 871-882 ◽  
Author(s):  
A.-S. F. OBADA ◽  
H. A. HESSIAN ◽  
A.-B. A. MOHAMED

An analytical method to calculate the sub-entropies and entanglement for the mixed state as an initial field is presented. Also, we investigate the effects of the atomic motion and the field-mode structure on sub-entropies and phase properties of the coherent superposition state and a statistical mixture of coherent states as initial field states taking into account different forms of the intensity-dependent coupling. The initial state, the atomic motion and the field-mode structure play important roles in the time evolution of the entropies, entanglement and phase properties.


2015 ◽  
Vol 15 (13&14) ◽  
pp. 1223-1232
Author(s):  
Chengjun Wu ◽  
Bin Luo ◽  
Hong Guo

When Alice and Bob share two pairs of quantum correlated states, Alice can remotely prepare quantum entanglement and quantum discord in Bob’s side by measuring the parts in her side and telling Bob the measurement results by classical communication. For remote entanglement preparation, entanglement is necessary . We find that for some shared resources having the same amount of entanglement, when Bell measurement is used, the entanglement remotely prepared can be different, and more discord in the resources actually decreases the entanglement prepared. We also find that for some resources with more entanglement, the entanglement remotely prepared may be less. Therefore, we conclude that entanglement is a necessary resource but may not be the only resource responsible for the entanglement remotely prepared, and discord does not likely to assist this process. Also, for the preparation of discord, we find that some states with no entanglement could outperform entangled states.


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