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.

scholarly journals A Treatment of the Absorption Spectrum for a Multiphoton -Type Three-Level Atom Interacting with a Squeezed Coherent Field in the Presence of Nonlinearities

2011 ◽  
Vol 2011 ◽  
pp. 1-11
Author(s):  
F. K. Faramawy
Keyword(s):  
Absorption Spectrum ◽  
Photon Number ◽  
Single Mode ◽  
Field Coupling ◽  
Multiphoton Transition ◽  
Mode Field ◽  
Dressed States ◽  
Level Atom ◽  
Coherent Field ◽  
Intensity Dependent Coupling

We study the interaction of a three-level atom with a single mode field through multiphoton transition in a cavity, taking explicitly into account the existence of forms of nonlinearities of both the field and the intensity-dependent atom-field coupling. The analytical forms of the absorption spectrum is calculated using the dressed states of the system. The effects of photon multiplicities, mean photon number, detuning, Kerr-like medium, and the intensity-dependent coupling functional on the absorption spectrum are analyzed.

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.

scholarly journals Study of Squeezing Properties in a Two-level System

1995 ◽  
Vol 48 (6) ◽  
pp. 907 ◽  
Author(s):  
Rui-hua Xie ◽  
Gong-ou Xu ◽  
Dun-huan Liu
Keyword(s):  
Single Mode ◽  
Nonlinear Interactions ◽  
Level System ◽  
Rotating Wave Approximation ◽  
Wave Approximation ◽  
Mode Field ◽  
Level Atom ◽  
Rotating Wave ◽  
Arbitrary Intensity ◽  
Intensity Dependent Coupling

We have studied the squeezing properties of a field and atom in a two-level system. The influence of nonlinear interactions (Le. the arbitrary intensity-dependent coupling of a single-mode field to a single two-level atom, the nonlinear interaction of the field with a nonlinear Kerr-like medium) on the squeezing is discussed in detail in the rotating wave approximation (RWA). We show numerically that the effect of the virtual-photon field suppresses dipole squeezing predicted in the RWA and leads to an increased squeeze revival period; the suppressed squeezing can be revived due to the presence of the nonlinear Kerr-like medium.

MOVING FOUR-LEVEL ATOM INTERACTING WITH A SINGLE-MODE FIELD WITH INTENSITY DEPENDENT COUPLING

2004 ◽  
Vol 18 (20n21) ◽  
pp. 2901-2914
Author(s):  
R. A. ZAIT
Keyword(s):  
Photon Number ◽  
Single Mode ◽  
Cavity Field ◽  
Field Coupling ◽  
Mode Field ◽  
Level Atom ◽  
The Mean ◽  
Reduced Density ◽  
Field Wave ◽  
Intensity Dependent Coupling

We study the interaction of a moving four-level atom with a single mode cavity field. Involving intensity dependent coupling, the atom-field wave function and the reduced density matrix of the field are obtained when the atom is initially prepared in a coherent superposition of the upper and ground states and the field is initially in a coherent state. The influence of the intensity dependent atom-field coupling and of the detuning on the collapse and revival phenomenon of the time evolution of statistical aspects, such as the mean photon number, the second-order correlation function of the field, the momentum increment and momentum diffusion, are investigated. It is found that, for the nonresonant case, the detuning between the field and the atom has a significant influence which leads to increasing the collapse time with decreasing amplitude. Numerical computations and discussion of the results are presented.

Assigning Values and States

2017 ◽  
Author(s):  
Richard Healey
Keyword(s):  
Quantum State ◽  
Density Operator ◽  
Entangled State ◽  
Physical Situation ◽  
Born Rule ◽  
Correct Assignment ◽  
Significant Magnitude ◽  
Good Advice ◽  
Empirical Significance ◽  
Important Idea

If a quantum state is prescriptive then what state should an agent assign, what expectations does this justify, and what are the grounds for those expectations? I address these questions and introduce a third important idea—decoherence. A subsystem of a system assigned an entangled state may be assigned a mixed state represented by a density operator. Quantum state assignment is an objective matter, but the correct assignment must be relativized to the physical situation of an actual or hypothetical agent for whom its prescription offers good advice, since differently situated agents have access to different information. However this situation is described, it is true, empirically significant magnitude claims that make the description correct, while others provide the objective grounds for the agent’s expectations. Quantum models of environmental decoherence certify the empirical significance of these magnitude claims while also licensing application of the Born rule to others without mentioning measurement.

SOME FEATURES OF SQUEEZED NEGATIVE BINOMIAL STATE

1992 ◽  
Vol 06 (03n04) ◽  
pp. 409-415 ◽  
Author(s):  
AMITABH JOSHI ◽  
S. V. LAWANDE
Keyword(s):  
Electromagnetic Field ◽  
Density Matrix ◽  
Wigner Function ◽  
Negative Binomial ◽  
Thermal State ◽  
Photon Number ◽  
Binomial State ◽  
Relationship Of ◽  
The Relationship ◽  
Photon Number Distribution

Properties of electromagnetic field in the squeezed negative binomial state are investigated in terms of photon number distribution and Wigner function. The relationship of the density matrix of the squeezed negative binomial state to the density matrix of the squeezed thermal state is shown explicitly. The possibility of generation of the negative binomial state is also discussed.

Coherence preservation in 3-level atom

2011 ◽  
Vol 11 (5&6) ◽  
pp. 420-433
Author(s):  
Fei Yang ◽  
Shuang Cong
Keyword(s):  
Ground State ◽  
Numerical Experiments ◽  
Control Object ◽  
System Model ◽  
Level System ◽  
Multilevel System ◽  
Control Field ◽  
Object A ◽  
Breakdown Time ◽  
Level Atom

Coherence preservation of a multilevel system subject to Markovian decoherence is studied. A Lambda-type three-level atom is selected as the system model. Coherence preservation between a ground state and the excited state of such a system is defined as the control object. A control field is designed by means of constraining the constant coherence condition. For the singularities of the control field, we qualitatively analyze the breakdown time, i.e. the time of control diverging. We obtain the region in which the state stays to maintain coherence forever in the case that the three-level system is reduced to a two-level one. For other cases, we investigate how different parameters affect the breakdown time qualitatively. Numerical experiments are implemented on a three-level quantum system and the experimental results are analyzed.

scholarly journals Field Squeezing in a Quantum-Dot Molecule Jaynes-Cummings Model

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Xu Chu ◽  
Xiaodong Ma ◽  
Ying Wang ◽  
Qingchun Zhou ◽  
Yu Zhou
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Number Field ◽  
Electron Tunneling ◽  
Photon Number ◽  
Electron Interaction ◽  
Coherent Field ◽  
Physical Quantities

We investigate the field squeezing in a system composed of an initial coherent field interacting with two quantum dots coupled by electron tunneling. An approximate quantum-dot molecule Jaynes-Cummings model describing the system is given, and the effects of physical quantities, such as the temperature, phonon-electron interaction, mean photon number, field detuning, and tunneling-level detuning, are discussed in detail.

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