Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physical Review A

Effects of spontaneously generated coherence on two-photon correlation in a double-cascade scheme

C. H. Raymond Ooi

Published Apr 26, 2007• 6 citations
Publisher

Abstract

We study the effect of spontaneously generated coherence (SGC) on two-photon correlation in a double-cascade scheme. An analytical expression for two-photon correlation is obtained and analyzed. The SGC and asymmetry in the two cascade channels provide a ``sinelike'' interference term that distorts the profile of the correlation. We show that the SGC term contains nonclassical features that are identical to the spontaneous Raman electromagnetic-induced transparency scheme which shows antibunching. Yet the correlation shows bunching instead of antibunching, and this is explained. We consider all possible transitions and find that photon antibunching is not possible in the double-cascade scheme.

DOI
10.1103/physreva.75.043818

Related papers

Effects of Spontaneously Generated Coherence on Intensity-Intensity Correlation in a Driven Y-Type Atom

Fei Wang, Wen-Xing Shi, Cheng Gong

In this paper, we investigate the spontaneously generated coherence (SGC) effects on the fluorescence fields intensity-intensity correlation in a resonant driven four-level Y-type atomic system. By using a strong control field, in the absense of SGC effects, strong correlation and anticorrelation fluorescence photons can be produced from two ladder transitions in this system respectively. However, in the presence of SGC effects, the fluorescence fields correlation properties are reversed for the two transitions. The above phenomena can be traced to the quantum destructive or constructive interference in terms of dressed states.

Communications in Theoretical Physics•Dec 1, 2011•6 citations

Two-photon correlation in a cascade amplifier: Propagation effects via a simple model, nonclassical regimes, and validity of neglecting Langevin noise

C. H. Raymond Ooi, Marlan O. Scully

We study several aspects of two-photon correlation of an optically driven extended medium (amplifier) with parametric down-conversion (PDC) scheme and three-level cascade scheme. The correlation for the PDC scheme is modeled by coupled parametric equations with constant self-coupling and cross coupling coefficients. This provides simple physical insights to how the correlation profile depends on the sign and magnitude of the coefficients in the presence of propagation group delay between signal and idler photons. The results with constant coefficients are related to the results of the driven three-level cascade scheme obtained from quantum Langevin-Maxwell's equations. The correlation transforms from bunching to antibunching as the pump field increases. Cauchy-Schwartz inequality is violated for all time delay in the case of off-resonant pump, showing nonclassical correlation. We verify that the correlation obtained without noise operators is qualitatively correct regardless of the optical density, especially for large detuning. We also discuss the interesting physics behind antibunching and oscillations found in the reverse correlation.

Physical Review A•Oct 16, 2007•16 citations

The influence of spontaneously generated coherence on atom-photon entanglement in a Λ-type system with an incoherent pump

Xin Yang, Dong Yan, Qian-Qian Bao +2 more

Abstract Owing to interference induced by spontaneous emission, the density-matrix equations in a three-level Λ-type system have an additional coherence term, which plays a critical role in modulating the inversionless gain and electromagnetically induced transparency effect. In addition, it is shown that spontaneously generated coherence (SGC) has an effect on the entanglement between an atom and a photon of the coupling laser field by calculating the degree of entanglement (DEM) of the atomic system. In this paper, we investigate the influence of the SGC effect on atom-photon entanglement in a Λ-type system, which generally remains a high entangled state. When an incoherent pump source is introduced, we find that the SGC effect could exert considerable influence on the atom reduced entropy under certain conditions for both transient and steady states. More interestingly, such an incoherent pump field could actively affect the short-time dynamic behaviors of the transient quantum entangled state at a certain range of pump rate as a typical coherent case.

Open Physics•Aug 26, 2014•4 citations

Investigation of spontaneously generated coherence in dressed states of ^85Rb atoms

Chun-Liang Wang, Aijun Li, Xu-Yi Zhou +3 more

We investigate the effects of spontaneously generated coherence (SGC) on the electromagnetically induced transparency features in a four-level Lambda-type system. We show that double-transparency windows and a controllable narrow absorption peak can be obtained with the presence of SGC. We present an equivalent system without the rigorous requirement of close-lying levels to observe the phenomena. We also experimentally demonstrate the corresponding features in a rubidium atomic beam.

Optics Letters•Mar 27, 2008•50 citations

Effects of spontaneously induced coherence on laser without population inversion in a four-level Λ-type system

Weicheng Chen

The coherence of a four-level Λ-type system with spontaneously generated coherence(SGC) is studied.With a weak probe and a strong coupling fields,whether the atomic system is on two-photon resonance or not,there is light without population inversion(LWI) on the probe field.On two-photon resonance,LWI is strengthened by SGC.On non-two-photon resonance,LWI can be controlled simply by adjusting the parameter of SGC and the two-upper-level separation.Meanwhile,the analytical solutions to the SGC parameter where LWI occurs are given in both cases.

Journal of Foshan University•Jan 1, 2007•0 citations

Decay-Induced Interference Effect on Photon Correlation in a Nearly Equispaced Three-Level Ladder Atom

Yao Chen, Fei Wang, Wen-Xing Shi +1 more

We investigate the effect of decay-induced interference on photon correlation in a nearly equispaced three-level driven ladder atom. It is found that the combination of destructive interference and two-photon resonance are responsible for the occurrence of nonclassical correlations. In addition, the bunching or antibunching behavior of the two emission processes can be controlled by the relative phase of the two applied fields attributed to the phase control spontaneous emission enhancement or cancellation.

Chinese Physics Letters•Nov 1, 2012•2 citations
We study the effect of spontaneously generated coherence (SGC) on two-photon correlation in a double-cascade scheme. An analytical expression for two-photon correlation is obtained and analyzed. The SGC and asymmetry in the two cascade channels provide a ``sinelike'' interference term that distorts the profile of the correlation. We show that the SGC term contains nonclassical features that are identical to the spontaneous Raman electromagnetic-induced transparency scheme which shows antibunching. Yet the correlation shows bunching instead of antibunching, and this is explained. We consider all possible transitions and find that photon antibunching is not possible in the double-cascade scheme.
In this paper, we investigate the spontaneously generated coherence (SGC) effects on the fluorescence fields intensity-intensity correlation in a resonant driven four-level Y-type atomic system. By using a strong control field, in the absense of SGC effects, strong correlation and anticorrelation fluorescence photons can be produced from two ladder transitions in this system respectively. However, in the presence of SGC effects, the fluorescence fields correlation properties are reversed for the two transitions. The above phenomena can be traced to the quantum destructive or constructive interference in terms of dressed states.
We study several aspects of two-photon correlation of an optically driven extended medium (amplifier) with parametric down-conversion (PDC) scheme and three-level cascade scheme. The correlation for the PDC scheme is modeled by coupled parametric equations with constant self-coupling and cross coupling coefficients. This provides simple physical insights to how the correlation profile depends on the sign and magnitude of the coefficients in the presence of propagation group delay between signal and idler photons. The results with constant coefficients are related to the results of the driven three-level cascade scheme obtained from quantum Langevin-Maxwell's equations. The correlation transforms from bunching to antibunching as the pump field increases. Cauchy-Schwartz inequality is violated for all time delay in the case of off-resonant pump, showing nonclassical correlation. We verify that the correlation obtained without noise operators is qualitatively correct regardless of the optical density, especially for large detuning. We also discuss the interesting physics behind antibunching and oscillations found in the reverse correlation.
Abstract Owing to interference induced by spontaneous emission, the density-matrix equations in a three-level Λ-type system have an additional coherence term, which plays a critical role in modulating the inversionless gain and electromagnetically induced transparency effect. In addition, it is shown that spontaneously generated coherence (SGC) has an effect on the entanglement between an atom and a photon of the coupling laser field by calculating the degree of entanglement (DEM) of the atomic system. In this paper, we investigate the influence of the SGC effect on atom-photon entanglement in a Λ-type system, which generally remains a high entangled state. When an incoherent pump source is introduced, we find that the SGC effect could exert considerable influence on the atom reduced entropy under certain conditions for both transient and steady states. More interestingly, such an incoherent pump field could actively affect the short-time dynamic behaviors of the transient quantum entangled state at a certain range of pump rate as a typical coherent case.
The coherence of a four-level Λ-type system with spontaneously generated coherence(SGC) is studied.With a weak probe and a strong coupling fields,whether the atomic system is on two-photon resonance or not,there is light without population inversion(LWI) on the probe field.On two-photon resonance,LWI is strengthened by SGC.On non-two-photon resonance,LWI can be controlled simply by adjusting the parameter of SGC and the two-upper-level separation.Meanwhile,the analytical solutions to the SGC parameter where LWI occurs are given in both cases.
We investigate the effect of decay-induced interference on photon correlation in a nearly equispaced three-level driven ladder atom. It is found that the combination of destructive interference and two-photon resonance are responsible for the occurrence of nonclassical correlations. In addition, the bunching or antibunching behavior of the two emission processes can be controlled by the relative phase of the two applied fields attributed to the phase control spontaneous emission enhancement or cancellation.