REDUCING FOUR-LEVEL TWO-MODE HAMILTONIAN TO AN EFFECTIVE TWO-LEVEL HAMILTONIAN WITH THE ADDITION OF KERR-LIKE MEDIUM

2010 ◽  
Vol 24 (01) ◽  
pp. 109-124 ◽  
Author(s):  
M. A. A. EL-DEBERKY ◽  
M. F. M. ALI
Keyword(s):  
Coherent State ◽  
Cascade Process ◽  
Effective Hamiltonian ◽  
Atomic Inversion ◽  
Level Atom ◽  
Quantized Field

We consider a two-mode quantized field described in a coherent state interacting with a four-level atom. An effective Hamiltonian is obtained by adiabatically eliminating the intermediate two levels in a cascade process. The influence of the Stark shifts and the Kerr-like medium on the atomic inversion are examined, as well as on the field entropy, atomic purity and Mandel's Q-parameter. The results of the calculations are illustrated numerically.

ENTANGLEMENT OF A TWO-LEVEL ATOM INTERACTING WITH A NEW STRUCTURE OF A GENERALIZED NONLINEAR STARK SHIFT VIA Ξ CONFIGURATION

2011 ◽  
Vol 25 (19) ◽  
pp. 2621-2636 ◽  
Author(s):  
E. M. KHALIL ◽  
M. M. A. AHMED ◽  
A.-S. F. OBADA
Keyword(s):  
Optical Cavity ◽  
Center Of Mass ◽  
Single Mode ◽  
Stark Shift ◽  
Mass Motion ◽  
Shift Parameter ◽  
Atomic Inversion ◽  
Level Atom ◽  
Quantized Field ◽  
Q Function

The problem of a two-level atom interacting with single mode cavity field is considered, however, the optical cavity is filled with new structure of a generalized nonlinear Stark shift via Ξ configuration. One starts with a three-level trapped atom interacting with the quantized field of center of mass motion thus a Hamiltonian for one-phonon process with nonlinearities is derived. Through the elimination of the intermediate level by using the adiabatic elimination method, we generate a new structure of effective Hamiltonian for a two-level atom with a nonlinear Stark shift. The temporal evolution of the atomic inversion is studied, we introduce that in the presence of the Stark shift parameter the atom leaves in a maximal entangled sate. We use the von Neuman entropy to measure the degree of entanglement between the atom and the field. After adding the nonlinear Stark shift the system never reaches the pure state. Also we study the Q-function for obtaining more information in phase space for this system. These aspects are sensitive to changes in the Stark shift parameter. The results shows that the effect of the nonlinearity in the Stark shift changes the quasiperiod of the field entropy and hence the entanglement between the particle and the field.

Introduction, generation and entanglement of entangled displaced even and odd squeezed states

2021 ◽  
pp. 2050047
Author(s):  
Amir Karimi
Keyword(s):  
Quantum States ◽  
Entangled States ◽  
Squeezed States ◽  
Displacement Operator ◽  
Text Type ◽  
Level Atom ◽  
Displacement Parameter ◽  
Entangled Quantum States ◽  
Quantized Field ◽  
Classical Fields

In this paper, first, we introduce special types of entangled quantum states named “entangled displaced even and odd squeezed states” by using displaced even and odd squeezed states which are constructed via the action of displacement operator on the even and odd squeezed states, respectively. Next, we present a theoretical scheme to generate the introduced entangled states. This scheme is based on the interaction between a [Formula: see text]-type three-level atom and a two-mode quantized field in the presence of two strong classical fields. In the continuation, we consider the entanglement feature of the introduced entangled states by evaluating concurrence. Moreover, we study the influence of the displacement parameter on the entanglement degree of the introduced entangled states and compare the results. It will be observed that the concurrence of the “entangled displaced odd squeezed states” has less decrement with respect to the “entangled displaced even squeezed states” by increasing the displacement parameter.

Schmidt decomposition in the interaction of a three-level atom and a quantized field

2018 ◽  
Vol 72 (10) ◽  
Author(s):  
Jorge A. Anaya-Contreras ◽  
Arturo Zúñiga-Segundo ◽  
Aldo Espinosa-Zúñiga ◽  
Francisco Soto-Eguibar ◽  
Héctor M. Moya-Cessa
Keyword(s):  
Schmidt Decomposition ◽  
Level Atom ◽  
Quantized Field

scholarly journals Two-level atom in a cross cavity

2013 ◽  
Vol 23 ◽  
pp. 31-34
Author(s):  
J. C. García-Melgarejo ◽  
J. J. Sánchez-Mondragón ◽  
K. J. Sánchez-Pérez ◽  
O. S. Magaña-Loaiza
Keyword(s):  
Wave Function ◽  
Electromagnetic Fields ◽  
Canonical Transformation ◽  
Evolution Operator ◽  
Atomic Inversion ◽  
Time Evolution Operator ◽  
Level Atom ◽  
Weak Intensity ◽  
Cavity Configuration ◽  
Intensity Regime

In this work we propose a model to analyze the interaction of a two-level atom (TLA) placed in a cross cavity configuration interacting with two electromagnetic fields injected within the cavity. A canonical transformation for field operators is proposed to obtain ef­fective Hamiltonian such as that of Jaynes-Cummings and we calculate the wave function via time-evolution operator. We present results for the atomic inversion for a state in the weak intensity regime.

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.

ENTROPY AND ENTANGLEMENT OF THE SUPERPOSITIONS OF DISPLACED FOCK STATES WITH A TWO-LEVEL ATOM

2006 ◽  
Vol 20 (11n13) ◽  
pp. 1269-1279
Author(s):  
GAMAL M. ABD AL-KADER
Keyword(s):  
Temporal Evolution ◽  
Photon Number ◽  
Time Dependent ◽  
Kerr Medium ◽  
Matrix Elements ◽  
Atomic Inversion ◽  
Fock States ◽  
Level Atom ◽  
Careful Investigation ◽  
Photon Number Distribution

The properties of the displaced Fock states (DFS's) superpositions are reviewed. The interaction of these states with a two-level atom in cavity with the presence of additional Kerr medium is studied. Exact general matrix elements of the time-dependent operators of a Jaynes-Cummings model (JCM), in the presence of a Kerr medium, with these states are derived. The atomic inversion and photon number distribution are discussed. The quantum entropy and the entanglement of the atom-field are investigated. The exact results are employed to perform a careful investigation of the temporal evolution of the entropy. The connection between the field entropy and the collapses and revivals of the atomic inversion has been established. The general conclusions reached are illustrated by numerical results.

AN ALGEBRAIC APPROACH TO THE INTERACTION OF A THREE-LEVEL ATOM INTERACTING WITH QUANTIZED RADIATION FIELD

2000 ◽  
Vol 14 (14) ◽  
pp. 1459-1471
Author(s):  
XU-BO ZOU ◽  
JING-BO XU ◽  
XIAO-CHUN GAO ◽  
JIAN FU
Keyword(s):  
Algebraic Structure ◽  
Evolution Operator ◽  
Algebraic Approach ◽  
Algebraic Method ◽  
Time Evolution Operator ◽  
Level Atom ◽  
Unitary Transformations ◽  
Quantized Field ◽  
Quantized Radiation Field ◽  
Multiphoton Interaction

The system of a three-level atom in the Ξ configuration coupled to two quantized field modes with arbitrary detuning and density-dependent multiphoton interaction is studied by dynamical algebraic method. With the help of an su(3) algebraic structure, we diagonalize the Hamiltonian by making use of unitary transformations and obtain the eigenvalues, eigenstates and time evolution operator for the system. Based on this su(3) structure, we also show that the system of a three-level atom in the Ξ configuration can be exactly transformed to an effective two-level Hamiltonian by an unitary transformation. Finally, we show that there exist an su (N) algebraic structure in the system of a N-level atom interacting with N-1 field modes.

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