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.

scholarly journals Hydrogen spin oscillations in a background of axions and the 21-cm brightness temperature

2020 ◽  
Author(s):  
G Lambiase ◽  
S Mohanty
Keyword(s):  
Cosmic Strings ◽  
Transition Rates ◽  
Spin Temperature ◽  
Level Atom ◽  
Spin Flip ◽  
Coherent Field ◽  
Unique Method ◽  
Photon Process ◽  
The Right ◽  
The Universe

Abstract The 21-cm line signal arising from the hyperfine interaction in hydrogen has an important role in cosmology and provides a unique method for probing of the universe prior to the star formation era. We propose that the spin flip of Hydrogen by the coherent emission/absorption of axions causes a lowering of their spin temperature and can explain the stronger than expected absorption of 21-cm light reported by the EDGES collaboration. We find the analogy of axion interaction with the two level HI with the Jaynes-Cummings model of a two level atom in a cavity and we derive the spin flip frequency in this formalism and show that the coherent oscillations frequency Ω∝1/fa in contrast with the incoherent transitions between the HI hyperfine levels where the transition rates $\propto 1/f_a^2$. The axion emission and absorption rates are equal but the spin temperature is still lowered due to different selection rules for the spin flip transitions compared to the photon process. We show that the axion process goes in the right direction for explaining the EDGES observation. For this mechanism to work we require a coherent field of relativistic axions with energy Eν peaked at the 21-cm spin-flip energy. Such a coherent background of relativistic axions can arise from the decay of cosmic strings if the decay takes place in the electroweak era.

TWO-LEVEL ATOM UNDERGOING TWO PHOTON TRANSITION IN A QUANTIZED FIELD: THE FLUORESCENT SPECTRUM

1992 ◽  
Vol 06 (12) ◽  
pp. 729-736
Author(s):  
AMITABH JOSHI ◽  
S. V. LAWANDE
Keyword(s):  
Fluorescence Spectrum ◽  
Two Photon ◽  
Photon Transition ◽  
Dressed States ◽  
Level Atom ◽  
Coherent Field ◽  
Fluorescent Spectrum ◽  
Qualitative Nature ◽  
Quantized Field ◽  
The Mean

The fluorescence spectrum produced by a two-photon Jaynes-Cummings model (JCM) has been analyzed using the infinity of transitions among the dressed states of its Hamiltonian. A large number of resonances in the spectra are observed which are sensitive to the mean photon numbers of the quantized coherent field. Also, the qualitative nature of these spectra are in contrast to that of the corresponding spectra of standard JCM.

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 dynamics of two two-level atoms interacting nonsymmetrically with a single-mode quantized field

2014 ◽  
Vol 88 (12) ◽  
pp. 1271-1274
Author(s):  
Y. Ma ◽  
J. Wang ◽  
X. Xu ◽  
W. Qi ◽  
J. Liu ◽  
...  
Keyword(s):  
Single Mode ◽  
Entanglement Dynamics ◽  
Quantized Field

MIXED-STATE ENTANGLEMENT IN A SINGLE-COOPER-PAIR BOX DETUNED WITH A COHERENT FIELD

2011 ◽  
Vol 25 (21) ◽  
pp. 2889-2894
Author(s):  
ZHAOXIN LI ◽  
YAN XU ◽  
LUYIN ZHANG ◽  
DA CHEN
Keyword(s):  
Mixed State ◽  
Cooper Pair ◽  
Single Mode ◽  
Resonant System ◽  
Cooper Pair Box ◽  
Coherent Field ◽  
Partial Transpose ◽  
Quantized Field

A system composed of a single-Cooper-pair box irradiated by a single-mode quantized field has been considered. The entanglement relative to the mixedness μ and the detuning δ is investigated with negative partial transpose. It is found that in the case of initial mixed state, the entanglement is weakened, but increases as time evolves. For a detuned system, the entanglement is further suppressed but more stationary than that for a resonant system.

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.

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 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.

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