scholarly journals Optimal entanglement generation in cavity QED with dissipation

2009 ◽  
Vol 87 (9) ◽  
pp. 1031-1036 ◽  
Author(s):  
Jian-Song Zhang ◽  
Jing-Bo Xu
Keyword(s):  
Density Matrix ◽  
Time Evolution ◽  
Cavity Qed ◽  
Density Operator ◽  
Interaction Time ◽  
Entanglement Generation ◽  
Driving Field ◽  
Level Atom ◽  
Field Environment ◽  
Dissipative Environment

We investigate a two-level atom coupled to a cavity with a strong classical driving field in a dissipative environment and find an analytical expression for the time evolution density matrix for the system. The analytical density operator is then used to study the entanglement between the atom and cavity by considering the competing process between the atom–field interactions and the field–environment interactions. It is shown that there is an optimal interaction time for generating atom–cavity entanglement.

scholarly journals NON-HERMITIAN QUANTUM DYNAMICS OF A TWO-LEVEL SYSTEM AND MODELS OF DISSIPATIVE ENVIRONMENTS

2013 ◽  
Vol 27 (27) ◽  
pp. 1350163 ◽  
Author(s):  
ALESSANDRO SERGI ◽  
KONSTANTIN G. ZLOSHCHASTIEV
Keyword(s):  
Time Evolution ◽  
Density Operator ◽  
Quantum Dynamics ◽  
Population Difference ◽  
Level System ◽  
Different Types ◽  
Dissipative Environments ◽  
Dissipative Environment

We consider a non-Hermitian Hamiltonian in order to effectively describe a two-level system (TLS) coupled to a generic dissipative environment. The total Hamiltonian of the model is obtained by adding a general anti-Hermitian part, depending on four parameters, to the Hermitian Hamiltonian of a tunneling TLS. The time evolution is formulated and derived in terms of the normalized density operator of the model, different types of decays are revealed and analyzed. In particular, the population difference and coherence are defined and calculated analytically. We have been able to mimic various physical situations with different properties, such as dephasing, vanishing population difference and purification.

Density matrix and purity evolution in dissipative two-level systems: II. Relaxation

2021 ◽  
Author(s):  
Sambarta Chatterjee ◽  
Nancy Makri
Keyword(s):  
Density Matrix ◽  
Time Evolution ◽  
Reduced Density Matrix ◽  
Level System ◽  
Two Level Systems ◽  
Reduced Density ◽  
Harmonic Bath

We investigate the time evolution of the reduced density matrix (RDM) and its purity in the dynamics of a two-level system coupled to a dissipative harmonic bath, when the system is initially placed in one of its eigenstates.

Time Evolution for a Three-level Atom in Interaction with Two Modes

1987 ◽  
Vol 34 (5) ◽  
pp. 665-677 ◽  
Author(s):  
A.-S.F. Obada ◽  
A.M. Abdel-Hafez
Keyword(s):  
Time Evolution ◽  
Level Atom

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.

FIELD PURIFICATION OF A GENERAL THREE-LEVEL SYSTEM INTERACTING WITH RADIATION

2003 ◽  
Vol 17 (07) ◽  
pp. 253-262 ◽  
Author(s):  
MAHMOUD ABDEL-ATY
Keyword(s):  
Exact Solution ◽  
Electromagnetic Field ◽  
Density Operator ◽  
Photon Number ◽  
Entangled State ◽  
Level System ◽  
Level Atom ◽  
Coherent Field ◽  
Field Purity ◽  
Intensity Dependent Coupling

In this essay we introduce a new Hamiltonian which represents the interaction between a three-level atom and a single electromagnetic field including arbitrary forms of nonlinearities of both the field and the intensity-dependent coupling. We derive an exact solution for the density operator of the system by means of which we study the field purity for the entangled state of the system. Also, the influences of the nonlinearities on the field purity and mean photon number are examined. Under the condition of an initial coherent field, the field purity shows the collapse-revival phenomenon. It is found that features of these phenomenon are sensitive to the changes of different kinds of the nonlinearities.

Time evolution of quantum-memory-assisted entropic uncertainty relation and quantum correlations under dissipative environment

2019 ◽  
Vol 17 (01) ◽  
pp. 1950008 ◽  
Author(s):  
Mohammad Reza Pourkarimi
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Time Evolution ◽  
Uncertainty Relation ◽  
Quantum Correlations ◽  
Quantum Memory ◽  
Xy Model ◽  
Anisotropic Parameter ◽  
Entropic Uncertainty Relation ◽  
Dissipative Environment

By assuming the effect of dissipative environment and the Hamiltonian XY-model and external magnetic field, the time evolution of the entropic uncertainty relation (EUR) in the presence of quantum-memory and the dynamics of quantum correlations (QC) are investigated. It is shown that EUR and QC may evolve in different ways during the time. However, they can behave similarly when the time tends to infinity. The effects of external magnetic field and anisotropic parameter are different on the dynamics of EUR and QC.

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