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:2501.06136

Hidden entanglement in twin beams generated through optical parametric amplification in hot alkali atoms

R. L. Rincón Celis, Gaurav Nirala, A. Montaña Guerrero, T.L. Meireles, M. Martinelli, A. M. Marino, H. M. Florez

Published Jan 10, 2025• 0 citations
arXivHTMLPDF

Abstract

Proper characterization of quantum correlations in a multimode optical state is critical for applications in quantum information science; however, the most common entanglement measurements can lead to an incomplete state reconstruction. This is the case for the ubiquitous spectral measurement of field quadratures for which a full characterization of the quantum correlations between optical beams is not possible. We demonstrate this effect in twin beams generated through parametric amplification by four-wave mixing in hot rubidium vapor, showing the role of a frequency dependent gain response. We implement a resonator-based measurement that reveals entanglement between beams that is otherwise hidden by usual spectral measurements. Additionally, this system shows how the phase shifts between the carrier and the sidebands on the involved fields affect the observation of entanglement for different entanglement witnesses, demonstrating the relevance of making a complete state tomography.

DOI
10.48550/arxiv.2501.06136

Related papers

Uncovering Hidden Entanglement in Twin Beams

R. L. Rincón Celis, Gaurav Nirala, A. Montaña Guerrero +5 more

Proper characterization of quantum correlations in multimode optical quantum states is critical for applications in quantum information science. However, standard entanglement measurements can lead to incomplete state reconstruction and characterization. Here, we implement a resonator-based detection system that reveals entanglement between sideband modes of twin beams, achieving full tomography and retrieving often ignored quantum correlations. Unlike standard spectral measurements such as homodyne detection, resonator detection can independently address the sidebands of each beam, thereby accessing these hidden correlations. Additionally, we show how phase shifts between the carrier and the sideband modes of the involved fields redistribute information and modify the observation of entanglement for different witnesses. The ability of the resonant detection to independently address sideband modes of entangled states can contribute to enhancing the capacity for secure communication and quantum networking protocols.

Physical Review Letters•Jul 16, 2026•0 citations

Sideband four-mode entanglement in a Four-wave mixing process

Raul Leonardo Rincon Celis

We present a detailed characterization of the entanglement in a stimulated Fourwave mixing process.This process is widely studied by the homodyne detection, a technique insensitive to the details of the sideband modes of the involved beams.The emission profile of the FWM process in atomic media shows an imbalance in the amplification of the sidebands, which suggest an asymmetry in the entanglement of the generated states, that can not be observed by the homodyne detection.The stimulated FWM consists on a single frequency pump and a seed beam interacting with the hot rubidium atoms, generating a pair of entangled states, the probe and the conjugated.By the implementation of the resonantor detection, we revealed the hidden entanglement structure of the generated beams.We found that the usual characterization of the state through the homodyne detection is incomplete.On the contrary, the reconstruction of the covariance matrix from the resonant detection allows the full characterization of the quantum correlations and a more complete entanglement structure between the sideband frequency modes.Therefore, with the measurement using resonant detection over a Four-wave mixing process, we can demonstrate the advantage of the detection to reveal entanglement that would be hidden if the usual two-mode description is used.

•Oct 25, 2022•0 citations

Multipartite Entangled Light From Above-Threshold Parametric Oscillation in Hot Rubidium Atoms

A. Montaña Guerrero, R. L. Rincón Celis, Gaurav Nirala +6 more

We demonstrate entanglement among four sideband spectral modes of twin beams generated in hot rubidium vapor. Parametric oscillation from high gain in a low-finesse cavity enables tailoring quantum states useful for information protocols.

Frontiers in Optics•Jan 1, 2022•0 citations

Continuous Variable Entanglement in an Optical Parametric Oscillator Based on a Nondegenerate Four Wave Mixing Process in Hot Alkali Atoms

A. Montaña Guerrero, R. L. Rincón Celis, P. Nussenzveig +3 more

We present the measurement of entanglement between twin beams generated with a doubly resonant optical parameter oscillator (OPO) based on four-wave mixing in hot ^{85}Rb vapor above threshold. This is the first measurement of entanglement in an OPO with a χ^{(3)} media above threshold. We reconstruct the covariance matrix for several configurations and based on a full picture of the four side band mode state, we study entanglement between all possible bipartitions. We show a robust generation of entanglement with stronger generation for a specific pair of modes. For this system, we show that atomic density is a determinant factor for the generation and loss of quantum correlations. The generation of entangled fields with an atomic OPO operating close to atomic resonance of alkali atoms enables a natural integration into quantum networks.

arXiv:2204.02920•Physical Review Letters•Oct 11, 2022•12 citations

Quantum Entanglement in a Double-Resonant Optical Parametric Oscillator (OPO) based on Hot Rubidium Vapour

A. Montaña Guerrero, R. L. Rincón Celis, P. Nussenzveig +3 more

We demonstrate the first measurement of entanglement between the twin beams generated by an OPO based on four-wave mixing in 85Rb above the threshold. We reconstruct the covariance matrix by using the method of resonator detection.

Conference on Lasers and Electro-Optics•Jan 1, 2022•0 citations

Generation of tripartite squeezed state by cascaded four-wave mixing in single hot rubidium atomic system

Changbiao Li, Yufeng Li, Wei Li +4 more

Abstract We report the quantum correlated triple beams via cascaded four-wave mixing (CFWM) amplified in single hot atomic vapor. Experimentally, we show that strong quantum correlation of three light beams, among them any two’s quantum correlation is characterized by the maximum value of intensity-difference squeezing (IDS) about −7.8 ± 0.3 dB. We found there is IDS between two idler beams, because two pairs of Einstein–Podolsky–Rosen injections potentially exist in our system. Besides, CFWM can emit three-mode beams at three different frequencies, in which these beams can be well separated in the spatial domain. Moreover, much difference with other methods, the injecting probe field can manipulate the gain and IDS of output three-mode light beams, which is resulting from competition relationship between cascaded two four-wave mixing processes. More interestingly, Autler–Townes splitting of gain peaks of output signals due to dressing effect of pumping fields, will lead to the evolution of measured two- and three-mode IDS from single-mode to multi-mode at frequency domain. This result will provide a multimode quantum resource which can potentially realize multimode entanglement and quantum networks.

New Journal of Physics•Aug 30, 2022•11 citations
Proper characterization of quantum correlations in a multimode optical state is critical for applications in quantum information science; however, the most common entanglement measurements can lead to an incomplete state reconstruction. This is the case for the ubiquitous spectral measurement of field quadratures for which a full characterization of the quantum correlations between optical beams is not possible. We demonstrate this effect in twin beams generated through parametric amplification by four-wave mixing in hot rubidium vapor, showing the role of a frequency dependent gain response. We implement a resonator-based measurement that reveals entanglement between beams that is otherwise hidden by usual spectral measurements. Additionally, this system shows how the phase shifts between the carrier and the sidebands on the involved fields affect the observation of entanglement for different entanglement witnesses, demonstrating the relevance of making a complete state tomography.
Proper characterization of quantum correlations in multimode optical quantum states is critical for applications in quantum information science. However, standard entanglement measurements can lead to incomplete state reconstruction and characterization. Here, we implement a resonator-based detection system that reveals entanglement between sideband modes of twin beams, achieving full tomography and retrieving often ignored quantum correlations. Unlike standard spectral measurements such as homodyne detection, resonator detection can independently address the sidebands of each beam, thereby accessing these hidden correlations. Additionally, we show how phase shifts between the carrier and the sideband modes of the involved fields redistribute information and modify the observation of entanglement for different witnesses. The ability of the resonant detection to independently address sideband modes of entangled states can contribute to enhancing the capacity for secure communication and quantum networking protocols.
We present a detailed characterization of the entanglement in a stimulated Fourwave mixing process.This process is widely studied by the homodyne detection, a technique insensitive to the details of the sideband modes of the involved beams.The emission profile of the FWM process in atomic media shows an imbalance in the amplification of the sidebands, which suggest an asymmetry in the entanglement of the generated states, that can not be observed by the homodyne detection.The stimulated FWM consists on a single frequency pump and a seed beam interacting with the hot rubidium atoms, generating a pair of entangled states, the probe and the conjugated.By the implementation of the resonantor detection, we revealed the hidden entanglement structure of the generated beams.We found that the usual characterization of the state through the homodyne detection is incomplete.On the contrary, the reconstruction of the covariance matrix from the resonant detection allows the full characterization of the quantum correlations and a more complete entanglement structure between the sideband frequency modes.Therefore, with the measurement using resonant detection over a Four-wave mixing process, we can demonstrate the advantage of the detection to reveal entanglement that would be hidden if the usual two-mode description is used.
We present the measurement of entanglement between twin beams generated with a doubly resonant optical parameter oscillator (OPO) based on four-wave mixing in hot ^{85}Rb vapor above threshold. This is the first measurement of entanglement in an OPO with a χ^{(3)} media above threshold. We reconstruct the covariance matrix for several configurations and based on a full picture of the four side band mode state, we study entanglement between all possible bipartitions. We show a robust generation of entanglement with stronger generation for a specific pair of modes. For this system, we show that atomic density is a determinant factor for the generation and loss of quantum correlations. The generation of entangled fields with an atomic OPO operating close to atomic resonance of alkali atoms enables a natural integration into quantum networks.
Abstract We report the quantum correlated triple beams via cascaded four-wave mixing (CFWM) amplified in single hot atomic vapor. Experimentally, we show that strong quantum correlation of three light beams, among them any two’s quantum correlation is characterized by the maximum value of intensity-difference squeezing (IDS) about −7.8 ± 0.3 dB. We found there is IDS between two idler beams, because two pairs of Einstein–Podolsky–Rosen injections potentially exist in our system. Besides, CFWM can emit three-mode beams at three different frequencies, in which these beams can be well separated in the spatial domain. Moreover, much difference with other methods, the injecting probe field can manipulate the gain and IDS of output three-mode light beams, which is resulting from competition relationship between cascaded two four-wave mixing processes. More interestingly, Autler–Townes splitting of gain peaks of output signals due to dressing effect of pumping fields, will lead to the evolution of measured two- and three-mode IDS from single-mode to multi-mode at frequency domain. This result will provide a multimode quantum resource which can potentially realize multimode entanglement and quantum networks.