ENTROPY GROWTH AND DEGRADATION OF ENTANGLEMENT DUE TO DAMPING OF THE ATOMIC DECAY IN THE JC MODEL

2008 ◽  
Vol 22 (23) ◽  
pp. 4017-4025 ◽  
Author(s):  
H. A. HESSIAN
Keyword(s):  
Exact Solution ◽  
Temporal Evolution ◽  
Single Mode ◽  
Total Entropy ◽  
High Q ◽  
Negative Eigenvalues ◽  
Level Atom ◽  
Jc Model ◽  
Entropy Growth ◽  
Degree Of Entanglement

In this presentation, we considered the atomic decay (but not for the cavity) for a two-level atom interacting with a single mode of electromagnetic field. The exact solution of the master equation in the case of a high-Q cavity with atomic decay is found. The effects of the atomic damping for a thermal reservoir on the temporal evolution of partial entropies of the atom or the field, and the total entropy as a quantitative entanglement, was measured. The degree of entanglement, through the sum of the negative eigenvalues of the partially transposed density matrix and the negative mutual information, has been studied and compared with other measures.

ENTROPY GROWTH INDUCED BY A SQUEEZED FIELD WITH A PHASE-DAMPING RESERVOIR

2009 ◽  
Vol 23 (25) ◽  
pp. 4993-5001
Author(s):  
A.-S. F. OBADA ◽  
H. A. HESSIAN ◽  
A.-B. A. MOHAMED
Keyword(s):  
Temporal Evolution ◽  
Single Mode ◽  
Initial Field ◽  
High Q ◽  
Phase Damping ◽  
Level Atom ◽  
Squeezed Coherent State ◽  
Entanglement Measures ◽  
Field State ◽  
Entropy Growth

A system of a two level atom interacting with a multi-photon single mode of electromagnetic field and damped with a phase reservoir is considered. The squeezed coherent state is taken as initial field state. The exact solution of the master equation in the case of a high-Q cavity is found. The effects of phase damping on the temporal evolution of some quantitative entanglement measures between the states of the system are investigated.

ENTANGLEMENT OF A GENERAL FORMALISM Ξ-TYPE THREE-LEVEL ATOM INTERACTING WITH A SINGLE-MODE FIELD IN THE PRESENCE OF NONLINEARITIES

2009 ◽  
Vol 23 (09) ◽  
pp. 2269-2283 ◽  
Author(s):  
A.-S. F. OBADA ◽  
A. A. EIED ◽  
G. M. ABD AL-KADER
Keyword(s):  
Unitary Operator ◽  
Temporal Evolution ◽  
Initial Density ◽  
Photon Number ◽  
Single Mode ◽  
Field Coupling ◽  
Mode Field ◽  
Level Atom ◽  
The Mean ◽  
Careful Investigation

We investigate the evolution of the atomic quantum entropy and the atom-field entanglement in a system of a Ξ-configuration three-level atom interacting with a single-mode field with additional forms of nonlinearities of both the field and the intensity-dependent atom-field coupling. With the derivation of the unitary operator within the frame of the dressed state and the exact results for the state of the system, we perform a careful investigation of the temporal evolution of the entropy. A factorization of the initial density operator is assumed, considering the field to be initially in a squeezed coherent or binomial state. The effects of the mean photon number, detuning, Kerr-like medium and the intensity-dependent coupling functional on the entropy are analyzed.

ENTANGLEMENT OF A GENERAL FORMALISM Λ-TYPE THREE-LEVEL ATOM INTERACTING WITH A SINGLE-MODE FIELD IN THE PRESENCE OF NONLINEARITIES

2009 ◽  
Vol 23 (15) ◽  
pp. 3241-3254 ◽  
Author(s):  
A.-S. F. OBADA ◽  
A. A. EIED ◽  
G. M. ABD AL-KADER
Keyword(s):  
Unitary Operator ◽  
Temporal Evolution ◽  
Initial Density ◽  
Photon Number ◽  
Single Mode ◽  
Field Coupling ◽  
Mode Field ◽  
Level Atom ◽  
The Mean ◽  
Careful Investigation

We investigate the evolution of the atomic quantum entropy and the atom–field entanglement in a system of a Λ-configuration three-level atom interacting with a single-mode field with additional forms of nonlinearities of both the field and the intensity-dependent atom–field coupling. With the derivation of the unitary operator within the frame of the dressed state and the exact results for the state of the system, we perform a careful investigation of the temporal evolution of the entropy. A factorization of the initial density operator is assumed, considering the field to be initially in a squeezed coherent or binomial state. The effects of the mean photon number, detuning, Kerr-like medium, and the intensity-dependent coupling functional on the entropy are analyzed.

ENTANGLEMENT AND PHOTON DYNAMICS IN THE INTERACTION BETWEEN TWO QUANTIZED ELECTROMAGNETIC FIELDS AND 3-LEVEL ATOMS

2011 ◽  
Vol 09 (01) ◽  
pp. 593-605 ◽  
Author(s):  
B. VASEGHI ◽  
G. REZAEI ◽  
R. KHORDAD ◽  
A. FALLAH ZADEH
Keyword(s):  
Coherent State ◽  
Electromagnetic Fields ◽  
Atomic System ◽  
Single Mode ◽  
The Other ◽  
Level Atom ◽  
Number State ◽  
Fock State ◽  
The Mean ◽  
Degree Of Entanglement

We study in this paper the dynamics of two electromagnetic (EM) fields and their entanglement in the interaction with a 3-level atom (Λ-configuration). We investigate the interaction when initially one of the fields is in a single mode coherent state, and the other one is in a Fock(number) state. We have calculated the mean photon numbers of the fields and their entanglement by means of the fields entropy as a measure of it. The results show the synchronization between entanglement beats and collapses-revivals of the fields, which cause the field in the Fock state (noncoherent) to behave coherently during the interaction. Also the results offer a way to generate coherent fields and achieve any desired degree of entanglement with specified dynamics via controlling the parameters of the atomic system.

The influence of the classical homogenous gravitational field on interaction of a three-level atom with a single mode cavity field

2015 ◽  
Vol 29 (29) ◽  
pp. 1550175 ◽  
Author(s):  
N. H. Abd El-Wahab ◽  
Ahmed Salah
Keyword(s):  
Electromagnetic Field ◽  
Gravitational Field ◽  
Photon Number ◽  
Single Mode ◽  
Temporal Behavior ◽  
Cavity Field ◽  
Text Type ◽  
Level Atom ◽  
The Mean ◽  
Single Mode Cavity

We study the interaction between a single mode electromagnetic field and a three-level [Formula: see text]-type atom in the presence of a classical homogenous gravitational field when the atom is prepared initially in the momentum eigenstate. The model includes the detuning parameters and the classical homogenous gravitational field. The wave function is calculated by using the Schrödinger equation for a coherent electromagnetic field and an atom is in its excited state. The influence of the detuning parameter and the classical homogenous gravitational field on the temporal behavior of the mean photon number, the normalized second-order correlation function and the normal squeezing is analyzed. The results show that the presence of these parameters has an important effect on these phenomena. The conclusion is reached and some features are given.

A FOUR-LEVEL ATOM INTERACTING WITH A SINGLE-MODE CAVITY FIELD: DOUBLE Ξ-CONFIGURATION

2008 ◽  
Vol 22 (26) ◽  
pp. 2587-2599 ◽  
Author(s):  
N. H. ABDEL-WAHAB
Keyword(s):  
Coherent State ◽  
Time Evolution ◽  
Single Mode ◽  
Cavity Field ◽  
Field System ◽  
Input Field ◽  
Level Atom ◽  
Constants Of Motion ◽  
Q Function ◽  
Single Mode Cavity

In this article, the problem of a double Ξ-type four-level atom interacting with a single-mode cavity field is considered. The considered model describes several distinct configurations of a four-level atom. Also, this model includes the detuning parameters of the atom-field system. We obtain the constants of motion and the wavefunction is derived when the atom is initially prepared in the upper state. We used this model for computing a number of the field aspects for the considered system. As an illustration, the model is used for studying the time evolution of the Mandel Q-parameter, amplitude-squared squeezing phenomenon and Q-function when the input field is considered in a coherent state. The results show that these phenomena are affected by the presence of detuning parameters.

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