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.

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.

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.

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.

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

2008 ◽  
Vol 22 (15) ◽  
pp. 2463-2471 ◽  
Author(s):  
RANJANA PRAKASH ◽  
PRAMILA SHUKLA
Keyword(s):  
Rabi Frequency ◽  
Second Harmonic ◽  
Single Mode ◽  
Coherent Radiation ◽  
Perturbation Approach ◽  
Radiation Wavelength ◽  
Rabi Oscillations ◽  
Atomic Inversion ◽  
Revival Time

We report here results for collapses and revivals phenomenon for a collection of M two-level atoms contained in a volume having dimensions much smaller than the radiation wavelength and existing in the Dicke state |r,m〉. We use a perturbation approach and obtain in the lowest contributing order of perturbation second harmonic, besides the main Rabi frequency. The amplitude of the fundamental depends on m only, but the amplitude of the harmonic has dependence on r as well as m. If the atoms are in superradiant states, only the second harmonic is obtained. Revival time for the second harmonic is one half that for the fundamental. It is interesting to note that the number of atoms M does not matter in Rabi frequency, collapse times, revival times or in amplitudes, and only r and m matter. Values of r and m of atoms in a Dicke state can be determined, in principle, by observing Rabi oscillations and average atomic inversion.

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.

Single-mode and two-mode squeezing in the three-level atom

1992 ◽  
Vol 70 (5) ◽  
pp. 379-382
Author(s):  
A. M. Abdel-Hafez
Keyword(s):  
Coherent States ◽  
Single Mode ◽  
Photon Interaction ◽  
Two Photon ◽  
Level Atom ◽  
The One ◽  
Photon Interactions

We investigate the phenomena of single-mode and two-mode squeezing for a three-level atom and two modes. The field modes are initially taken in coherent states. The effects of detuning on these phenomena are studied for one-photon and two-photon interactions. The relation between the collapse and revival phenomena and single-mode and two-mode squeezing is shown. It is found that the two-mode squeezing is much more effective than the single-mode squeezing for the one-photon interaction. While for the two-photon interaction the reverse is true.

scholarly journals The Jaynes–Cummings model of a two-level atom in a single-mode para-Bose cavity field

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
H. Fakhri ◽  
M. Sayyah-Fard
Keyword(s):  
Coherent States ◽  
Quantum Noise ◽  
Single Mode ◽  
Von Neumann Entropy ◽  
Cavity Field ◽  
Squeezing Effect ◽  
Atomic Inversion ◽  
Von Neumann ◽  
Level Atom ◽  
Mechanical Nature

AbstractThe coherent states in the parity deformed analog of standard boson Glauber coherent states are generated, which admit a resolution of unity with a positive measure. The quantum-mechanical nature of the light field of these para-Bose states is studied, and it is found that para-Bose order plays an important role in the nonclassical behaviors including photon antibunching, sub-Poissonian statistics, signal-to-quantum noise ratio, quadrature squeezing effect, and multi-peaked number distribution. Furthermore, we consider the Jaynes-Cummings model of a two-level atom in a para-Bose cavity field with the initial states of the excited and Glauber coherent ones when the atom makes one-photon transitions, and obtain exact energy spectrum and eigenstates of the deformed model. Nonclassical properties of the time-evolved para-Bose atom-field states are exhibited through evaluating the fidelity, evolution of atomic inversion, level damping, and von Neumann entropy. It is shown that the evolution time and the para-Bose order control these properties.

INTERACTION OF MESOSCOPIC JOSEPHSON JUNCTION WITH A SUCCESSIVE SQUEEZED COHERENT FIELD

2000 ◽  
Vol 14 (16) ◽  
pp. 609-618
Author(s):  
V. A. POPESCU
Keyword(s):  
Coherent State ◽  
Josephson Junction ◽  
Coherent States ◽  
Quantum Noise ◽  
Shapiro Steps ◽  
Superconducting Ring ◽  
Coherent Field ◽  
Current Voltage ◽  
Quantum Current ◽  
The Difference

Signal-to-quantum noise ratio for quantum current in mesoscopic Josephson junction of a circular superconducting ring can be improved if the electromagnetic field is in a successive squeezed coherent state. The mesoscopic Josephson junctions can feel the difference between the successive squeezed coherent states and other types of squeezed coherent states because their current–voltage Shapiro steps are different. We compare our method with another procedure for superposition of two squeezed coherent states (a squeezed even coherent state) and consider the effect of different large inductances on the supercurrent.

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