scholarly journals Quantum entanglement and position–momentum entropic squeezing of a moving Lambda-type three-level atom interacting with a single-mode quantized field with intensity-dependent coupling

2013 ◽  
Vol 46 (14) ◽  
pp. 145506 ◽  
Author(s):  
M J Faghihi ◽  
M K Tavassoly
Keyword(s):  
Quantum Entanglement ◽  
Single Mode ◽  
Level Atom ◽  
Quantized Field ◽  
Intensity Dependent Coupling

SQUEEZING OSCILLATIONS OF A QUANTIZED FIELD INTERACTING WITH PAIR OF COLD ATOMS VIA INTENSITY-DEPENDENT COUPLING

2007 ◽  
Vol 05 (01n02) ◽  
pp. 199-205 ◽  
Author(s):  
V. I. KOROLI
Keyword(s):  
Cold Atoms ◽  
Exact Analytical Solution ◽  
Single Mode ◽  
Initial Moment ◽  
Transition Elements ◽  
Level Atom ◽  
Field State ◽  
Quantized Field ◽  
Physical Quantities ◽  
Intensity Dependent Coupling

We study the interaction between a single-mode electromagnetic field and a pair of indistinguishable two-level atoms via the intensity-dependent coupling. This problem is equivalent to the equidistant three-level atom with equal dipole moment matrix transition elements between the adjacent levels. The exact analytical solution for the atom–field state-vector is obtained assuming that at the initial moment the field is in the Holstein–Primakoff SU (1,1) coherent state. The quantum statistical and squeezing properties of the field are investigated. The results obtained are compared with those for the single two-level atom obtained by Buzek. We observe that the exact periodicity of the field squeezing that takes place in the case of the single two-level atom is violated in the case of the pair of cold atoms. That is, the exact periodicity of the physical quantities can be destroyed only if the radiation field interacts with a system of more than one two-level atom.

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.

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.

ENTANGLEMENT FOR JAYNES CUMMINGS MODEL IN THE PRESENCE MULTI-PHOTON PROCESS UNDER DECOHERENCE EFFECT

2013 ◽  
Vol 11 (03) ◽  
pp. 1350026 ◽  
Author(s):  
S. ABDEL-KHALEK ◽  
M. S. ALMALKI
Keyword(s):  
Quantum Computer ◽  
Single Mode ◽  
Entanglement Dynamics ◽  
Nonlocal Correlation ◽  
Phase Damping ◽  
Level Atom ◽  
Coherent Field ◽  
Photon Process ◽  
Quantized Field ◽  
Decoherence Effect

The quantum nonlocal correlation between an atom and coherent field is described quantitatively in terms of multi-photon and phase damping processes. Especially, considering a two-level atom interacts with a single-mode quantized field in a coherent state inside a phase-damped cavity, and taking into account the number of multi-photon transitions and phase damping effect, the entanglement is investigated during the time evolution as a function of involved' parameters in the system. The results show that the enhancement of the transitions are very useful in generating a high amount of entanglement. Due to the significance of how a system is quantum correlated with its environment in the construction of a scalable quantum computer, the entanglement dynamics between the bipartite system with its environment is evaluated and investigated during the dissipative process. Finally, the physical interpretation of the correlation behaviors between the subsystems is explained through the statistical properties of the field.

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