Measure of general quantum correlations in optomechanics

2018 ◽  
Vol 16 (05) ◽  
pp. 1850043 ◽  
Author(s):  
M. Amazioug ◽  
M. Nassik ◽  
N. Habiballah
Keyword(s):  
Bath Temperature ◽  
Quantum Correlations ◽  
Atomic Ensemble ◽  
Thermal Bath ◽  
Optomechanical System ◽  
Optomechanical Systems ◽  
Squeezed Light ◽  
Quantum Steering ◽  
Quantum Equations ◽  
Gaussian Quantum Discord

In this paper, we analyze nonclassical correlations between bipartite states in two optomechanical systems. The first system (Sec. 2) consists of two nanoresonators spatially separated by broadband squeezed light, where each cavity has a fixed mirror and a movable one. The second system (Sec. 3) is an atom-optomechanical system consisting of an atomic ensemble placed inside an optical nanoresonator with a vibrating mirror. For both optomechanical systems, we give the Hamiltonian and the explicit expression of covariance matrix leading to the quantum equations describing the dynamic evolution of the system. Then, the nonclassical correlations are quantified using the logarithmic negativity and Gaussian quantum discord. We propose also a scheme for examining the evolution of Gaussian quantum steering and its asymmetry in each system. We show that the entanglement of the two mechanical modes is very strongly related to the parameters characterizing the environment where the movable mirrors evolve, in particular the squeeze parameter, the optomechanical cooperativity and thermal bath temperature.

Steady-state quantum correlation measurement in hybrid optomechanical systems

2020 ◽  
pp. 2050046
Author(s):  
Tesfay Gebremariam Tesfahannes ◽  
Merkebu Dereje Getahune
Keyword(s):  
Correlation Function ◽  
Steady State ◽  
Quantum Entanglement ◽  
Quantum Correlation ◽  
Optical Cavity ◽  
Quantum Correlations ◽  
Correlation Measurement ◽  
Atomic Ensemble ◽  
Optomechanical System ◽  
Optomechanical Systems

In this paper, we investigate the steady-state of quantum correlation measurement of hybrid optomechanical systems. The first system consists of a single optomechanical system simultaneously coupled to a mechanical oscillator. While the second system is a hybrid optomechanical system consisting of an atomic ensemble placed in between the optical cavity and mirror. For both optomechanical systems, we formulate the Hamiltonian and the explicit expression of the covariance matrix leading to the dynamic of the system. Under the linearization approximation, we investigate the steady-state quantum correlations which are quantified through the correlation function of non-Hermitian operators, while the logarithmic negativity is used to quantify the amount of quantum entanglement between the subsystems. Furthermore, our proposed quantum correlation function can be used to quantify the entangled bipartite states that are correlative and transfer information. It is found that the transfer of quantum correlations between the subsystem is related to the detuning and coupling strength. Our results provide a realistic route toward remote quantum entanglement detection and a framework of future realistic fiber-optic quantum network operating applications.

scholarly journals Entanglement versus Gaussian quantum discord in a double-cavity opto-mechanical system

2015 ◽  
Vol 13 (06) ◽  
pp. 1550041 ◽  
Author(s):  
J. El Qars ◽  
M. Daoud ◽  
Ahl Laamara
Keyword(s):  
Mechanical System ◽  
Quantum Discord ◽  
Analytical Formula ◽  
Bath Temperature ◽  
Quantum Correlations ◽  
Thermal Bath ◽  
Environment Effects ◽  
Optical Modes ◽  
Global Covariance ◽  
Gaussian Quantum Discord

In this paper, we investigate the robustness of the quantum correlations against the environment effects in various opto-mechanical bipartite systems. For two spatially separated opto-mechanical cavities, we give analytical formula for the global covariance matrix involving two mechanical modes and two optical modes. The logarithmic negativity as an indicator of the degree of entanglement and the Gaussian quantum discord which is a witness of quantumness of correlations are used as quantifiers to evaluate the different pairwise quantum correlations in the whole system. The evolution of the quantum correlations existing in this opto-mechanical system are analyzed in terms of the thermal bath temperature, squeezing parameter and the opto-mechanical cooperativity. We find that with desirable choice of these parameters, it is possible either to enhance or annihilate the quantum correlations in the system. Various scenarios are discussed in detail.

scholarly journals On Amplification of Light in the Continuous EPR State

2003 ◽  
Vol 01 (02) ◽  
pp. 207-215 ◽  
Author(s):  
V. N. Gorbachev ◽  
A. I. Trubilko
Keyword(s):  
Quantum Correlations ◽  
Continuous Variable ◽  
The Other ◽  
Atomic Ensemble ◽  
Transparent Medium ◽  
Integrals Of Motion ◽  
Squeezed Light ◽  
Type Interaction ◽  
Epr State

Two schemes of amplification of two-mode squeezed light in the continuous variable EPR-state are considered. They are based on the integrals of motion, which allow conserving quantum correlations whereas the power of each mode may increase. One of these schemes involves a three-photon parametric process in a nonlinear transparent medium and the other is a Raman type interaction of light with atomic ensemble. A generalization to multimode squeezed light is discussed.

Dynamics of classical-quantum correlations between two movable mirrors in optomechanics

2020 ◽  
Vol 34 (08) ◽  
pp. 2050066 ◽  
Author(s):  
M. Amazioug ◽  
L. Jebli ◽  
M. Nassik ◽  
N. Habiballah
Keyword(s):  
Thermal State ◽  
Quantum Correlations ◽  
Strong Coupling Regime ◽  
Squeezed Light ◽  
Fabry Perot ◽  
Classical Quantum ◽  
Rotating Wave ◽  
Quantum Mutual Information ◽  
Down Conversion ◽  
Gaussian Quantum Discord

We study the dynamics of classical-quantum correlations in the nonadiabatic regime, using the rotating wave approximation (RWA), between two movable mirrors of two spatially separated Fabry–Pérot cavities, each of the two cavities having a movable end-mirror and coupled to a two-mode squeezed light from spontaneous parametric down-conversion. This work completes our previous work [M. Amazioug, M. Nassik and N. Habiballah, Eur. Phys. J. D 72, 171 (2018)] where we have studied the transfer of quantum correlations in steady state. The Bures distance is used to quantify the amount of entanglement of the symmetrical squeezed thermal state, and the Gaussian quantum discord is considered to quantify the quantumness of the quantum correlations even though the two movable mirrors are separable. Furthermore, total correlations are quantified using quantum mutual information. Indeed, these three indicators depend mainly on the temperature of the movable mirror and the squeezing parameter in strong coupling regime.

scholarly journals Nonclassical correlations in a two-mode optomechanical system

2016 ◽  
Vol 30 (20) ◽  
pp. 1650134 ◽  
Author(s):  
J. El Qars ◽  
M. Daoud ◽  
R. Ahl Laamara
Keyword(s):  
Quantum Correlations ◽  
Optomechanical System ◽  
Squeezed Light ◽  
Wide Range ◽  
Optical Modes ◽  
System Temperature ◽  
Optomechanical Coupling ◽  
Two Hybrid

The pairwise quantum correlations in a tripartite optomechanical system comprising a mechanical mode and two optical modes are analyzed. The Simon criterion is used as a witness of the separability. Whereas the Gaussian discord is employed to capture the quantumness of correlations. Both entanglement and Gaussian discord are evaluated as functions of the parameters characterizing the environment and the system (temperature, squeezing and optomechanical coupling). We work in the resolved-sideband regime. We show that it is possible to reach three simultaneous bipartite entanglements via the quantum correlations transfer from the squeezed light to the system. While, even without squeezed light, the quantumness of correlations can be captured simultaneously between the three modes for a very wide range of parameters. Specifically, we find that the two optical modes exhibit more quantum correlations in comparison with the entangled mechanical–optical modes. Finally, unlike the two hybrid subsystems, the purely optical one seems more resilient against the environmental destructive effects.

Controlling nonclassical properties of optomechanical systems under the Coulomb interaction effect

2020 ◽  
Vol 18 (08) ◽  
pp. 2150002
Author(s):  
Abderrahim Lakhfif ◽  
Jamal El Qars ◽  
Mostafa Nassik
Keyword(s):  
Coulomb Interaction ◽  
Quantum Coherence ◽  
Quantum Correlations ◽  
Optomechanical System ◽  
Squeezed Light ◽  
Rotating Wave Approximation ◽  
Nonclassical Properties ◽  
Fabry Perot ◽  
Rotating Wave ◽  
Coulomb Effects

In an optomechanical system consisting of two Fabry–Pérot cavities fed by squeezed light and coupled via Coulomb interaction, we respectively use the logarithmic negativity, Gaussian discord and Gaussian coherence to analyze the behavior of three different indicators of nonclassicality, namely the entanglement, quantum discord and quantum coherence. We perform the rotating wave approximation and work in the resolved sideband regime. In two bi-mode states (optical and mechanical), the coherence is generally found to be greater than entanglement and discord. More interestingly, we show that the Coulomb interaction can be used either to degrade or enhance the nonclassical properties of the optical subsystem. In addition, compared with the discord and coherence, the mechanical entanglement is found strongly sensitive to both thermal and Coulomb effects, and it requires a minimum value of cooperativity to be generated. Remarkably, this minimum increases when increasing the Coulomb coupling strength. Finally, we notice that an optimal transfer of quantum correlations between the optical and mechanical subsystems is achieved in the absence of the Coulomb interaction.

Gaussian quantum discord and EPR steering in optomechanical system

Optik ◽  
2018 ◽  
Vol 158 ◽  
pp. 1186-1193 ◽  
Author(s):  
M. Amazioug ◽  
M. Nassik ◽  
N. Habiballah
Keyword(s):  
Quantum Discord ◽  
Optomechanical System ◽  
Gaussian Quantum Discord ◽  
Epr Steering

scholarly journals Optical Bistability in an Optomechanical System with N-Type Atoms under Nonresonant Conditions

Photonics ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 122
Author(s):  
Yan Gao ◽  
Li Deng ◽  
Aixi Chen
Keyword(s):  
Optical Bistability ◽  
Light Field ◽  
Photon Number ◽  
Optical Switches ◽  
Atomic Ensemble ◽  
Cavity Field ◽  
Bistable Behavior ◽  
Optomechanical System ◽  
The Mean ◽  
Nonlinear Distribution

In this paper, the phenomenon of the optical bistability of a cavity field is theoretically investigated in an optomechanical system containing an N-type atomic ensemble. In this hybrid optomechanical system, the atoms are coupled with two controlling light fields besides coupling with the cavity field. Under the nonresonant condition, we analyze the influences of the coupling strength between cavity and atoms, Rabi frequencies of the controlling light field, the detuning between the controlling light field and atoms, and pump field power on the optical bistable behavior of mean intracavity photon number. The nonlinear distribution of the mean intracavity photon number has a potential application in field optical switches and optical bistable devices.

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