scholarly journals Enhanced Squeezing and Entanglement in Nondegenerate Three-Level Laser Coupled to Squeezed Vacuum Reservoir

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Ebisa Mosisa
Keyword(s):  
Differential Equations ◽  
Cavity Mode ◽  
Photon Number ◽  
Intensity Difference ◽  
Normal Ordering ◽  
Symplectic Matrix ◽  
Squeezed Vacuum ◽  
Level Atom ◽  
Level Laser ◽  
The Mean

Squeezing and entanglement of a two-mode cascade laser, produced by a three-level atom which is initially prepared by a coherent superposition of the top and bottom levels then injected into a cavity coupled to a two-mode squeezed vacuum reservoir is discussed. I obtain stochastic differential equations associated with the normal ordering using the pertinent master equation. Making use of the solutions of the resulting differential equations, we determined the mean photon number for the cavity mode and their correlation, EPR variables, smallest eigenvalue of the symplectic matrix, intensity difference fluctuation, and photon number correlation. It is found that the squeezed vacuum reservoir increases the degree of the statistical and nonclassical features of light produced by the system. Furthermore, using the criteria developed by logarithm negativity and Hillery-Zubairy criteria, the quantum entanglement of the cavity mode is quantified. It is found that the degree of the entanglement for the system under consideration increases with the squeezing parameter of the squeezed vacuum reservoir.

scholarly journals A Bright Entanglement and Squeezing Generated by an External Pumping Radiation in a Correlated Emission Laser

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Chimdessa Gashu
Keyword(s):  
Cavity Mode ◽  
Nonlinear Crystal ◽  
Energy State ◽  
Photon Number ◽  
Statistical Properties ◽  
Intensity Difference ◽  
Normal Ordering ◽  
Cavity Modes ◽  
Correlation Properties ◽  
Correlated Emission

The quantum and statistical properties of light generated by an external classical field in a correlated emission laser with a parametric amplifier and coupled to a squeezed vacuum reservoir are investigated using the combination of the master and stochastic differential equations. First, the solutions of the cavity-mode variables and correlation properties of noise forces associated to the normal ordering are obtained. Next, applying the resulting solutions, the mean photon number of the separate cavity modes and their crosscorrelation, smallest eigenvalue of the symplectic matrix, mean photon number, intensity difference fluctuation, photon number variance, and intensity correlation are derived for the cavity-mode radiation. The entanglement produced is studied employing the logarithmic negativity criterion. It is found that pumping atoms from the lower energy state to excited state, introducing the nonlinear crystal into the cavity and coupling the system to a biased noise fluctuation, generate a bright and strong squeezing and entanglement with enhanced statistical properties although the atoms are initially in the ground state.

scholarly journals Coherently Driven N Number of Degenerate Three-Level Atoms with Parametric Amplifier

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Tamirat Abebe ◽  
Chimdessa Gashu ◽  
Nebiyu Gemechu
Keyword(s):  
Characteristic Function ◽  
Cavity Mode ◽  
Photon Number ◽  
Parametric Amplifier ◽  
Frequency Interval ◽  
Normal Order ◽  
Quantum Langevin Equation ◽  
Quadrature Squeezing ◽  
Level Laser ◽  
The Mean

We have analyzed the squeezing and statistical properties of the cavity light beam produced by a coherently driven degenerate three-level laser with a degenerate parametric amplifier (DPA) in an open cavity and coupled to a vacuum reservoir via a single-port mirror. We have carried out our analysis by putting the noise operators associated with the vacuum reservoir in normal order. Applying the solutions of the equations of evolution for the expectation values of the atomic operators and the quantum Langevin equation for the cavity mode operator, the mean photon number and the quadrature squeezing of the cavity light are calculated. And a large part of the mean photon number is confined in a relatively small frequency interval. Furthermore, we also obtain the antinormally ordered characteristic function defined in the Heisenberg picture. With the aid of the resulting characteristic function, we determine the Q function which is then used to calculate the photon number distribution.

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.

ENTANGLEMENT OF A GENERAL FORMALISM Ξ-TYPE THREE-LEVEL ATOM INTERACTING WITH A SINGLE-MODE FIELD IN THE PRESENCE OF NONLINEARITIES

2009 ◽  
Vol 23 (09) ◽  
pp. 2269-2283 ◽  
Author(s):  
A.-S. F. OBADA ◽  
A. A. EIED ◽  
G. M. ABD AL-KADER
Keyword(s):  
Unitary Operator ◽  
Temporal Evolution ◽  
Initial Density ◽  
Photon Number ◽  
Single Mode ◽  
Field Coupling ◽  
Mode Field ◽  
Level Atom ◽  
The Mean ◽  
Careful Investigation

We investigate the evolution of the atomic quantum entropy and the atom-field entanglement in a system of a Ξ-configuration three-level atom interacting with a single-mode field with additional forms of nonlinearities of both the field and the intensity-dependent atom-field coupling. With the derivation of the unitary operator within the frame of the dressed state and the exact results for the state of the system, we perform a careful investigation of the temporal evolution of the entropy. A factorization of the initial density operator is assumed, considering the field to be initially in a squeezed coherent or binomial state. The effects of the mean photon number, detuning, Kerr-like medium and the intensity-dependent coupling functional on the entropy are analyzed.

ENTANGLEMENT OF A GENERAL FORMALISM Λ-TYPE THREE-LEVEL ATOM INTERACTING WITH A SINGLE-MODE FIELD IN THE PRESENCE OF NONLINEARITIES

2009 ◽  
Vol 23 (15) ◽  
pp. 3241-3254 ◽  
Author(s):  
A.-S. F. OBADA ◽  
A. A. EIED ◽  
G. M. ABD AL-KADER
Keyword(s):  
Unitary Operator ◽  
Temporal Evolution ◽  
Initial Density ◽  
Photon Number ◽  
Single Mode ◽  
Field Coupling ◽  
Mode Field ◽  
Level Atom ◽  
The Mean ◽  
Careful Investigation

We investigate the evolution of the atomic quantum entropy and the atom–field entanglement in a system of a Λ-configuration three-level atom interacting with a single-mode field with additional forms of nonlinearities of both the field and the intensity-dependent atom–field coupling. With the derivation of the unitary operator within the frame of the dressed state and the exact results for the state of the system, we perform a careful investigation of the temporal evolution of the entropy. A factorization of the initial density operator is assumed, considering the field to be initially in a squeezed coherent or binomial state. The effects of the mean photon number, detuning, Kerr-like medium, and the intensity-dependent coupling functional on the entropy are analyzed.

Entanglement formulation in the framework of electrically pumped laser cavity

2016 ◽  
Vol 30 (06) ◽  
pp. 1650024
Author(s):  
Solomon Getahun
Keyword(s):  
Decay Constant ◽  
Photon Number ◽  
Laser Cavity ◽  
Entangled State ◽  
Normal Order ◽  
Quadrature Squeezing ◽  
Level Laser ◽  
Electrically Pumped ◽  
The Mean ◽  
Degree Of Entanglement

We analyze electrically pumped atomic cavity coupled to a two-mode vacuum reservoirs via a single-port mirror whose open cavity contains N nondegenerate three-level cascade atoms. We carry out our analysis by putting the noise operators associated with a vacuum reservoir in normal order. It is found that unlike the mean photon number, the quadrature squeezing and the degree of entanglement do not depend on the number of atoms. This implies that the quadrature squeezing and the degree of entanglement of the cavity light do not depend on the number of photons. We have also shown that the light generated by the three-level laser is in a squeezed and entangled state, with maximum quadrature squeezing and degree of entanglement being 50%. Moreover, the mean photon number of the system in which the laser operating at threshold and above threshold does not depend on the spontaneous decay constant.

scholarly journals The Effect of Superposition on the Quantum Features of the Cavity Radiation of a Three-Level Laser

2021 ◽  
Vol 66 (9) ◽  
pp. 761
Author(s):  
D. Ayehu ◽  
A. Chane
Keyword(s):  
Density Operator ◽  
Photon Number ◽  
Quantum Langevin Equation ◽  
Quantum Properties ◽  
Quadrature Squeezing ◽  
Level Laser ◽  
Cavity Radiation ◽  
The Mean ◽  
The Individual ◽  
Light Beams

We study the statistical and squeezing properties of the cavity light produced by a degenerate three-level laser with the use of the solution of the pertinent quantum Langevin equation. Moreover, applying the density operator to the cavity radiation superposition, we investigated the quantum properties of the superposed cavity light beams generated by a pair of degenerate three-level lasers. Superposing the cavity radiation increases the mean and the variance of the photon number without affecting the quadrature squeezing. It is observed that the degree of squeezing of the separate cavity radiation, as well as the superposed cavity radiation, increases with the rate at which the atoms are injected into the cavity. We have also shown that the mean photon number of the superposed cavity radiation is the sum of the mean photon numbers of the individual cavity radiation. However, the variance of the photon number of the superposed cavity radiation turns out to be four times that of the component cavity radiation.

scholarly journals Two-Mode Squeezed and Entangled Light Production in Parametric Oscillations

2021 ◽  
Vol 66 (8) ◽  
pp. 674
Author(s):  
D. Ayehu
Keyword(s):  
Photon Number ◽  
Langevin Equations ◽  
Pump Mode ◽  
Light Production ◽  
Squeezed Vacuum ◽  
The Mean ◽  
Parametric Oscillations

We investigate the statistical and quadrature squeezings, as well as the entanglement properties, of a two-mode light generated by non-degenerate parametric oscillations coupled to a two-mode squeezed vacuum reservoir, by employing the solutions of the quantum Langevin equations. It is found that the two-mode light shows the two-mode squeezing and entanglement for all values of the time. Moreover, it is observed that the squeezed vacuum reservoir and the growing amplitude of the pump mode enhance the degrees of two-mode squeezing and entanglement. We have also shown that the amounts of squeezing and entanglement are significant in a region, where the mean photon number is higher, and the photon number correlation is lower.

scholarly journals Two-Level Atom with Squeezed Light from Optical Parametric Oscillators

2018 ◽  
Vol 63 (7) ◽  
pp. 600 ◽  
Author(s):  
T. Abebe ◽  
N. Gemechu
Keyword(s):  
Power Spectrum ◽  
Cavity Mode ◽  
Photon Number ◽  
Parametric Amplifier ◽  
Fluorescent Light ◽  
Parametric Oscillators ◽  
Quantum Langevin Equation ◽  
Level Atom ◽  
Upper Level ◽  
Correlation Properties

The dynamics of a coherently driven two-level atom with parametric amplifier and coupled to a vacuum reservoir is analyzed. The combination of the master equation and the quantum Langevin equation is presented to study the quantum properties of light. By using these equations, we have determined the time evolution of the expectation values of the cavity mode and atomic operators. Moreover, with the aid of these results, the correlation properties of noise operators, and the large-time approximation scheme, we calculate the mean photon number, power spectrum, second-order correlation function, and quadrature variances for the cavity-mode light and fluorescence. It is found that the half-width of the power spectrum for the fluorescent light in the presence of a parametric amplifier increases, while it decreases for the cavity-mode light. Moreover, we have found the probability for the atom to be in the upper level in the presence of a parametric amplifier.

scholarly journals Quantum Entanglement and its Quantification in a Two-Mode Cascade Laser

2021 ◽  
pp. 1-8
Author(s):  
Ebisa Mosisa Kanea ◽  
Keyword(s):  
Master Equation ◽  
Quantum Entanglement ◽  
Normal Ordering ◽  
Logarithmic Negativity ◽  
Squeezed Vacuum ◽  
Level Laser ◽  
Cavity Radiation ◽  
Schwartz Inequality ◽  
Correlation Properties ◽  
Degree Of Entanglement

In this paper, quantum entanglement of correlated two-mode light generated by a three-level laser coupled to a two-mode squeezed vacuum reservoir is thoroughly analyzed using different inseparability criteria, using the master equation, we obtain the stochastic dierential equation and the correlation properties of the noise forces associated with the normal ordering. Next, we study the photon entanglement by considering different inseparability criteria. In particular, the criteria applied are Duan-Giedke-Cirac-Zoller (DGCZ) criterion, logarithmic negativity, Hillery-Zubairy, and Cauchy-Schwartz inequality and we found that the presence of the squeezing parameter leads to an increase in the degree of entanglement. Moreover, the linear gain coecient significantly achieved the degree of entanglement for the cavity radiation

Sign in / Sign up

Export Citation Format

Share Document