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

arXiv:2403.08395

Complementarity of which-path information in induced and stimulated coherences via four-wave mixing process from warm Rb atomic ensemble

Danbi Kim, Jiho Park, Baek, Changhoon, Sun Kyung Lee, Han Seb Moon

Published Mar 13, 2024• 0 citations
arXivHTMLPDF

Abstract

We report a systematic approach for establishing a complementary relationship between the interference visibility, concurrence, and predictability in the crossing of induced and stimulated coherences of two-mode squeezed coherent states. This is achieved using a double-path interferometer involving two independent four-wave mixing (FWM) atomic samples generated via spontaneous and stimulated FWM processes from a warm atomic ensemble of 87Rb. We demonstrate that the transition from quantum to classical behavior can be characterized by the induced coherence effect, distinguishing between the two-mode squeezed vacuum and coherent states. Moreover, our experimental scheme, employing two FWM atomic ensembles with long-coherent photons, provides valuable insights into the complementarity of which-path information in induced and stimulated coherences.

DOI
10.48550/arxiv.2403.08395

Related papers

Complementarity of which-path information in induced and stimulated coherences via four-wave mixing process from warm Rb atomic ensemble

Danbi Kim, Jiho Park, Changhoon Baek +2 more

Complementarity, a fundamental tenet of quantum optics, is indispensable for elucidating the fundamental principles of quantum physics and advancing quantum information processing applications. In the context of wave–particle duality, induced-coherence experiments were understood through the lens of which-path information. Conversely, the stimulated-coherence experiments were explained by using the indistinguishability of the photon statistics of conjugate photons as a means of realizing complementarity. Here, we report a systematic approach for establishing a complementary relationship between the interference visibility, concurrence, and predictability in the crossing of induced and stimulated coherences of two-mode squeezed coherent states. This is achieved using a double-path interferometer involving two independent four-wave mixing (FWM) atomic samples generated via spontaneous and stimulated FWM processes from a warm atomic ensemble of 87 Rb. We demonstrate that the transition from quantum to classical behavior can be characterized by the induced coherence effect, distinguishing between the two-mode squeezed vacuum and coherent states. Moreover, our experimental scheme, employing two FWM atomic ensembles with long-coherent photons, provides valuable insights into the complementarity of which-path information in induced and stimulated coherences.

Optica Quantum•Jul 17, 2024•4 citations

Induced Coherence via Spontaneous Four‐Wave Mixing in Atomic Ensembles

Jiho Park, Heonoh Kim, Han Seb Moon

Abstract Induced coherence was first demonstrated three decades ago in a proof‐of‐principle experiment using entangled photons from spontaneous parametric down‐conversion in nonlinear crystals. This phenomenon is considered an interesting instance of complementarity, which lies at the heart of quantum optics. Here, the first demonstration of induced coherence across two coupled interferometers based on spontaneous four‐wave mixing (SFWM) in two independent hot‐atomic‐vapor‐based entangled photon sources is reported. When both the pump and coupling lasers are split and interact with two warm 87 Rb atomic ensembles, single‐photon interference is observed between the two idler photons of the narrowband photon pairs, generated via SFWM from the two cascade‐type atomic systems. Furthermore, it is found that the phase memory effect arises from the phase of the bidirectional counter‐propagating pump and coupling lasers, respectively. This work takes an important step toward the transition to the era of quantum optics being driven by atomic ensembles from solid‐state systems.

Advanced Quantum Technologies•Jun 4, 2021•3 citations

Stimulated four-wave mixing in the cascade-type atomic system of a warm Cs atomic ensemble

Jongmin Hwang, Jiho Park, Heewoo Kim +1 more

We investigate stimulated four-wave mixing (FWM) in the 6S1/2–6P3/2–8S1/2 open transition of a warm 133Cs atomic ensemble. Despite the absence of the two-photon cycling transition, we measure high-contrast FWM signals in the 6P3/2–8S1/2 transition between the upper excited states according to the frequency detuning and powers of the coupling and driving lasers. The FWM light generation in the upper excited states is interpreted as the FWM phenomena induced by the driving laser of the 6S1/2–6P3/2 transition from the cascade-type two-photon coherent atomic ensemble with the coupling and pump lasers. We believe that this work can contribute to the development of hybrid photonic quantum networks between photonic quantum states generated from different atomic systems.

Optics Express•Nov 5, 2020•6 citations

Experimental studies of two-mode squeezed states in rubidium vapor

Alberto M. Marino

In this thesis we describe a series of calculations and experiments that use atomic coherence for the generation of two-mode squeezed states of the electromagnetic field. Atomic coherence makes it possible to eliminate the problems of absorption losses and spontaneous emission that have limited the amount of squeezing obtained with atomic systems. Effects such as electromagnetically induced transparency allow for efficient generation of atomic coherence and are used as the basis for the generation of squeezed states. We analyze the use of a double-A configuration in order to combine a four-wave mixing process and atomic coherence in a single system. The use of this configuration makes it possible to eliminate absorption and enhance the four-wave mixing process responsible for the generation of a two-mode squeezed state. We implemented a new detection technique, which we devised, based on the use of a bichromatic local oscillator in a balanced heterodyne detection scheme for the characterization of two-mode squeezed states. This new detection technique makes it possible to characterize squeezed states independently of the frequency separation between the modes. In order to obtain the required phase-coherent lasers, we designed and implemented a laser system that consists of three stabilized external-cavity diode lasers. We obtained a system with a residual phase noise of less than 0.04 rad². We studied electromagnetically induced transparency in the Dl line of ⁸⁷Rb and obtained a reduction in absorption of 92%. Experimentally, we implemented the double-A configuration in the Dl line of ⁸⁷Rb in a vapor cell. We were able to verify the presence of correlations between the fields generated from the four-wave mixing process and produced more than 10 decibels of phase-dependent noise modulation. Finally, we propose a new quantum communication scheme that takes advantage of the properties of a two-mode squeezed state. This new scheme offers the possibility of securely transmitting either a cryptographic key or a deterministic message. We analyze the security of the scheme and find that it can be verified with the use of the quantum correlations present in a two-mode squeezed state.

•Jan 1, 2006•2 citations

Complementarity in biphoton generation with stimulated or induced coherence

Axel Heuer, R. W. Menzel, Peter W. Milonni

Coherence can be induced or stimulated in parametric down-conversion using two or three crystals when, for example, the idler modes of the crystals are aligned. Previous experiments with induced coherence [Phys. Rev. Lett. 114, 053601 (2015)] focused on which-path information and the role of vacuum fields in realizing complementarity via reduced visibility in single-photon interference. Here we describe experiments comparing induced and stimulated coherence. Different single-photon interference experiments were performed by blocking one of the pump beams in a three-crystal setup. Each counted photon is emitted from one of two crystals and which-way information may or not be available, depending on the setup. Distinctly different results are obtained in the induced and stimulated cases, especially when a variable transmission filter is inserted between the crystals. A simplified theoretical model accounts for all the experimental results and is also used to address the question of whether the phases of the signal and idler fields in parametric down-conversion are correlated.

arXiv:1506.00457•Physical Review A•Sep 18, 2015•40 citations

Light manipulation via spontaneous four-wave mixing in a warm double-Λ-type atomic ensemble

Taek Jeong, Young-Tak Chough, Han Seb Moon

We report on the dynamic manipulation of light in a warm 87Rb atomic ensemble using light storage based on the atomic spin coherence arising from the electromagnetically induced transparency (EIT) and spontaneous four-wave mixing (FWM) processes. We demonstrate that, subsequent to the generation of atomic spin coherence between two hyperfine ground states via the EIT storage process, it is possible to control the delay time, direction, and optical frequency of the retrieved light according to the timing sequence and powers of the coupling, probe, and driving lasers used for atomic-spin-coherence generation and the spontaneous FWM process. We believe that our results provide useful ideas in photon frequency conversion and photon control in connection with the quantum memories that is essential in the quantum communications technology.

Optics Express•Nov 10, 2020•3 citations
We report a systematic approach for establishing a complementary relationship between the interference visibility, concurrence, and predictability in the crossing of induced and stimulated coherences of two-mode squeezed coherent states. This is achieved using a double-path interferometer involving two independent four-wave mixing (FWM) atomic samples generated via spontaneous and stimulated FWM processes from a warm atomic ensemble of 87Rb. We demonstrate that the transition from quantum to classical behavior can be characterized by the induced coherence effect, distinguishing between the two-mode squeezed vacuum and coherent states. Moreover, our experimental scheme, employing two FWM atomic ensembles with long-coherent photons, provides valuable insights into the complementarity of which-path information in induced and stimulated coherences.
Complementarity, a fundamental tenet of quantum optics, is indispensable for elucidating the fundamental principles of quantum physics and advancing quantum information processing applications. In the context of wave–particle duality, induced-coherence experiments were understood through the lens of which-path information. Conversely, the stimulated-coherence experiments were explained by using the indistinguishability of the photon statistics of conjugate photons as a means of realizing complementarity. Here, we report a systematic approach for establishing a complementary relationship between the interference visibility, concurrence, and predictability in the crossing of induced and stimulated coherences of two-mode squeezed coherent states. This is achieved using a double-path interferometer involving two independent four-wave mixing (FWM) atomic samples generated via spontaneous and stimulated FWM processes from a warm atomic ensemble of 87 Rb. We demonstrate that the transition from quantum to classical behavior can be characterized by the induced coherence effect, distinguishing between the two-mode squeezed vacuum and coherent states. Moreover, our experimental scheme, employing two FWM atomic ensembles with long-coherent photons, provides valuable insights into the complementarity of which-path information in induced and stimulated coherences.
Abstract Induced coherence was first demonstrated three decades ago in a proof‐of‐principle experiment using entangled photons from spontaneous parametric down‐conversion in nonlinear crystals. This phenomenon is considered an interesting instance of complementarity, which lies at the heart of quantum optics. Here, the first demonstration of induced coherence across two coupled interferometers based on spontaneous four‐wave mixing (SFWM) in two independent hot‐atomic‐vapor‐based entangled photon sources is reported. When both the pump and coupling lasers are split and interact with two warm 87 Rb atomic ensembles, single‐photon interference is observed between the two idler photons of the narrowband photon pairs, generated via SFWM from the two cascade‐type atomic systems. Furthermore, it is found that the phase memory effect arises from the phase of the bidirectional counter‐propagating pump and coupling lasers, respectively. This work takes an important step toward the transition to the era of quantum optics being driven by atomic ensembles from solid‐state systems.
We investigate stimulated four-wave mixing (FWM) in the 6S1/2–6P3/2–8S1/2 open transition of a warm 133Cs atomic ensemble. Despite the absence of the two-photon cycling transition, we measure high-contrast FWM signals in the 6P3/2–8S1/2 transition between the upper excited states according to the frequency detuning and powers of the coupling and driving lasers. The FWM light generation in the upper excited states is interpreted as the FWM phenomena induced by the driving laser of the 6S1/2–6P3/2 transition from the cascade-type two-photon coherent atomic ensemble with the coupling and pump lasers. We believe that this work can contribute to the development of hybrid photonic quantum networks between photonic quantum states generated from different atomic systems.
In this thesis we describe a series of calculations and experiments that use atomic coherence for the generation of two-mode squeezed states of the electromagnetic field. Atomic coherence makes it possible to eliminate the problems of absorption losses and spontaneous emission that have limited the amount of squeezing obtained with atomic systems. Effects such as electromagnetically induced transparency allow for efficient generation of atomic coherence and are used as the basis for the generation of squeezed states. We analyze the use of a double-A configuration in order to combine a four-wave mixing process and atomic coherence in a single system. The use of this configuration makes it possible to eliminate absorption and enhance the four-wave mixing process responsible for the generation of a two-mode squeezed state. We implemented a new detection technique, which we devised, based on the use of a bichromatic local oscillator in a balanced heterodyne detection scheme for the characterization of two-mode squeezed states. This new detection technique makes it possible to characterize squeezed states independently of the frequency separation between the modes. In order to obtain the required phase-coherent lasers, we designed and implemented a laser system that consists of three stabilized external-cavity diode lasers. We obtained a system with a residual phase noise of less than 0.04 rad². We studied electromagnetically induced transparency in the Dl line of ⁸⁷Rb and obtained a reduction in absorption of 92%. Experimentally, we implemented the double-A configuration in the Dl line of ⁸⁷Rb in a vapor cell. We were able to verify the presence of correlations between the fields generated from the four-wave mixing process and produced more than 10 decibels of phase-dependent noise modulation. Finally, we propose a new quantum communication scheme that takes advantage of the properties of a two-mode squeezed state. This new scheme offers the possibility of securely transmitting either a cryptographic key or a deterministic message. We analyze the security of the scheme and find that it can be verified with the use of the quantum correlations present in a two-mode squeezed state.
Coherence can be induced or stimulated in parametric down-conversion using two or three crystals when, for example, the idler modes of the crystals are aligned. Previous experiments with induced coherence [Phys. Rev. Lett. 114, 053601 (2015)] focused on which-path information and the role of vacuum fields in realizing complementarity via reduced visibility in single-photon interference. Here we describe experiments comparing induced and stimulated coherence. Different single-photon interference experiments were performed by blocking one of the pump beams in a three-crystal setup. Each counted photon is emitted from one of two crystals and which-way information may or not be available, depending on the setup. Distinctly different results are obtained in the induced and stimulated cases, especially when a variable transmission filter is inserted between the crystals. A simplified theoretical model accounts for all the experimental results and is also used to address the question of whether the phases of the signal and idler fields in parametric down-conversion are correlated.
We report on the dynamic manipulation of light in a warm 87Rb atomic ensemble using light storage based on the atomic spin coherence arising from the electromagnetically induced transparency (EIT) and spontaneous four-wave mixing (FWM) processes. We demonstrate that, subsequent to the generation of atomic spin coherence between two hyperfine ground states via the EIT storage process, it is possible to control the delay time, direction, and optical frequency of the retrieved light according to the timing sequence and powers of the coupling, probe, and driving lasers used for atomic-spin-coherence generation and the spontaneous FWM process. We believe that our results provide useful ideas in photon frequency conversion and photon control in connection with the quantum memories that is essential in the quantum communications technology.