Sub-Poissonian photon statistics of light in interaction of two-level atoms in superposed states with a single mode superposed coherent radiation

2010 ◽  
Vol 88 (3) ◽  
pp. 181-188 ◽  
Author(s):  
Rakesh Kumar ◽  
Hari Prakash
Keyword(s):  
Coherent State ◽  
Single Mode ◽  
Fano Factor ◽  
Coherent Radiation ◽  
Photon Statistics ◽  
Coupling Constant ◽  
Large Coupling ◽  
Definite Relationship ◽  
Level Atom ◽  
Coupling Time

We study sub-Poissonian photon statistics of light in interaction of a single mode radiation, initially either in a coherent state or in a superposed coherent state with an assembly of two-level atoms using the Hamiltonian, H = ω(a+a + Sz) + g(aS+ + a+ S–) in natural units, where a+ and a are creation and annihilation operators, Sz, S ± are the collective Dicke operators, g is the coupling constant, and ω is the energy of the photons and also the separation between the two atomic levels. We study the cases of (i) a single two-level and (ii) of two two-level atoms interacting with a single mode coherent or superposed coherent radiation. We find that for large coupling time gt, Fano factor shows collapses and revival phenomena, and that the variation is large for small mean number of photons. We also find that in the case of two two-level atoms, photon statistics shows larger sub-Poissonian than the case of a single two-level atom, and that there is no definite relationship between squeezing and sub-Poissonian photon statistics of light.

COLLAPSES AND REVIVALS IN TWO-LEVEL ATOMS IN A SUPERPOSED STATE INTERACTING WITH A SINGLE MODE SUPERPOSED COHERENT RADIATION

2008 ◽  
Vol 22 (17) ◽  
pp. 2725-2739 ◽  
Author(s):  
HARI PRAKASH ◽  
RAKESH KUMAR
Keyword(s):  
Coherent State ◽  
Large Amplitude ◽  
Coherent States ◽  
Single Mode ◽  
Coherent Radiation ◽  
Rabi Oscillations ◽  
Mean Frequency ◽  
Double Frequency ◽  
Level Atom ◽  
Superradiant State

Collapses and revivals phenomenon in system of a single two-level atom and two two-level atoms existing in some superposed states and interacting with a single mode superposed coherent radiation is studied. For superposed Dicke states |1/2, ±1/2> of a single two-level atom interacting with even or odd coherent state, only odd revivals occur. For two two-level atoms, it is found that the collapse and revival times for even and odd coherent states are equal to one half of the corresponding times for coherent state. For this system, Rabi oscillations occur with a main mean frequency and also some second harmonics are present, in general. However, if the two atoms are in the superradiant state, only the second harmonics with large amplitude are obtained. The appearance of weak double frequency revivals for superposed atomic and coherent states was studied and a condition for their disappearance is found.

ORDINARY SQUEEZING AND AMPLITUDE-SQUARED SQUEEZING OF A SINGLE MODE COHERENT RADIATION IN INTERACTION WITH TWO TWO-LEVEL ATOMS

2007 ◽  
Vol 21 (20) ◽  
pp. 3621-3642 ◽  
Author(s):  
HARI PRAKASH ◽  
RAKESH KUMAR
Keyword(s):  
Ground State ◽  
Photon Number ◽  
Single Mode ◽  
Energy Difference ◽  
Coherent Radiation ◽  
Atomic State ◽  
Square Root ◽  
Coupling Constant ◽  
Revival Time ◽  
Coupling Time

In the present paper, we consider the interaction of a single mode radiation initially in a coherent state with an assembly of two two-level atoms in some different states using the Hamiltonian, H = ω(a+a + Sz)+g(a S+ + a+ S-) in the natural units, where a+ and a are the creation and annihilation operators for radiation, Sz, S± are the collective Dicke operators, g is the coupling constant, ω is the energy of the photons and energy difference between the two atomic levels. We solve it exactly. We study ordinary squeezing and amplitude-squared squeezing of radiation for the general operators, [Formula: see text] and Yθ=1/2(a2e-iθ+a+2eiθ), when atoms are fully excited, super-radiant or in the ground state. We get a large ordinary squeezing (nearly 88% squeezing) for the super-radiant atomic state, at a time, which is 0.451 of the first revival time, and this should be easily observable. We also get a large amplitude-squared squeezing (nearly 20%) at the time, which is about 0.033 of the first revival time. Variation of variances near their minima with coupling time gt, square root of mean photon number |α| and phase are also discussed.

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.

scholarly journals DYNAMICS OF STATES IN THE NONLINEAR INTERACTION REGIME BETWEEN A THREE-LEVEL ATOM AND GENERALIZED COHERENT STATES AND THEIR NON-CLASSICAL FEATURES

2012 ◽  
Vol 26 (05) ◽  
pp. 1250027 ◽  
Author(s):  
M. K. TAVASSOLY ◽  
F. YADOLLAHI
Keyword(s):  
Coherent State ◽  
Coherent States ◽  
Exact Analytical Solution ◽  
Photon Number ◽  
Single Mode ◽  
Level Atom ◽  
Special Cases ◽  
Interaction Regime ◽  
Atomic Population Inversion ◽  
Poissonian Statistics

The present study investigates the interaction of an equidistant three-level atom and a single-mode cavity field that has been initially prepared in a generalized coherent state. The atom–field interaction is considered to be, in general, intensity-dependent. We suppose that the nonlinearity of the initial generalized coherent state of the field and the intensity-dependent coupling between atom and field are distinctly chosen. Interestingly, an exact analytical solution for the time evolution of the state of atom–field system can be found in this general regime in terms of the nonlinearity functions. Finally, the presented formalism has been applied to a few known physical systems such as Gilmore–Perelomov and Barut–Girardello coherent states of SU(1,1) group, as well as a few special cases of interest. Mean photon number and atomic population inversion will be calculated, in addition to investigating particular non-classicality features such as revivals, sub-Poissonian statistics and quadratures squeezing of the obtained states of the entire system. Also, our results will be compared with some of the earlier works in this particular subject.

ENTANGLEMENT AND PHOTON DYNAMICS IN THE INTERACTION BETWEEN TWO QUANTIZED ELECTROMAGNETIC FIELDS AND 3-LEVEL ATOMS

2011 ◽  
Vol 09 (01) ◽  
pp. 593-605 ◽  
Author(s):  
B. VASEGHI ◽  
G. REZAEI ◽  
R. KHORDAD ◽  
A. FALLAH ZADEH
Keyword(s):  
Coherent State ◽  
Electromagnetic Fields ◽  
Atomic System ◽  
Single Mode ◽  
The Other ◽  
Level Atom ◽  
Number State ◽  
Fock State ◽  
The Mean ◽  
Degree Of Entanglement

We study in this paper the dynamics of two electromagnetic (EM) fields and their entanglement in the interaction with a 3-level atom (Λ-configuration). We investigate the interaction when initially one of the fields is in a single mode coherent state, and the other one is in a Fock(number) state. We have calculated the mean photon numbers of the fields and their entanglement by means of the fields entropy as a measure of it. The results show the synchronization between entanglement beats and collapses-revivals of the fields, which cause the field in the Fock state (noncoherent) to behave coherently during the interaction. Also the results offer a way to generate coherent fields and achieve any desired degree of entanglement with specified dynamics via controlling the parameters of the atomic system.

The effects of atom–cavity coupling constant on physical observables for different transitions

2018 ◽  
Vol 96 (8) ◽  
pp. 919-925
Author(s):  
Babak Parvin
Keyword(s):  
Optical Cavity ◽  
Coherence Function ◽  
Photon Number ◽  
Single Mode ◽  
Coupling Constant ◽  
Photon Transition ◽  
Level Atom ◽  
Cavity Coupling ◽  
The Matrix ◽  
Field Correlation

The aim of this work is to investigate the changing effects of the atom–cavity coupling constant on an atom–cavity system. A three-level atom in the Λ configuration with q-photon transition between levels 2 and 3 is confined in a single-mode Fabry–Pérot optical cavity. To solve the master equation of this system in the steady-state by using the appropriate physical quantities, the matrix continued fractions method for recurrence equations is applied. The behavior of physical observables including atom–field correlation, mean photon number, and second-order coherence function is discussed. The effect of altering the atom–cavity coupling constant for different transitions on these observables is fully considered. The results of calculations show that by increasing this coupling constant, the range of atom–cavity correlation becomes longer, the maximum value of the output mean photon number from the cavity remains almost constant, the broadening in the curves of the mean photon number increases and the lasing process is amplified in the system. Finally, the transformation of the three-level atom into a two-level one under several specific conditions in a four-photon transition case has been studied. The obtained results of the two-level atomic pattern are adequately confirmed by the simulations related to the three-level atom.

Dynamics of an M-Level Atom Interacting with Cavity Fields: Properties of Photon Statistics

1989 ◽  
Author(s):  
Fu-Li Li ◽  
Xiao-Shen Li ◽  
D. L. Lin ◽  
Thomas F. George
Keyword(s):  
Photon Statistics ◽  
Level Atom

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.

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