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:2509.16675

Multipartite quantum entanglement in $\mathcal{PT}$-symmetric molecular optomechanics: Nonreciprocal enhancement and thermal resilience to \SI{500}{\kelvin}

E. Kongkui Berinyuy, Carolle Tchodimou, Philippe Djorwé, S. K. Singh, S. G. Nana Engo

Published Sep 20, 2025• 0 citations
arXivHTMLPDF

Abstract

We present a theoretical framework for a $\mathcal{PT}$-symmetric double-cavity molecular optomechanical system demonstrating nonreciprocal enhancement of multipartite quantum entanglement at elevated temperatures. All bipartite entanglement channels ($E_{ac}$, $E_{aB_1}$, $E_{cB_2}$, $E_{B_1B_2}$) simultaneously maximize at optimal nonreciprocal asymmetry $J_1/J_2 \approx 5$, with entanglement persisting to $T \sim \SIrange{400}{500}{\kelvin}$ (material-limited ceiling) two orders of magnitude beyond conventional optomechanical systems. This thermal resilience and balanced enhancement across all channels arise from synergistic combination of ultra-high-frequency molecular vibrations ($ω_m/2π= \SI{30}{\tera\hertz}$), collective $\sqrt{N}$ coupling enhancement with $N=\num{e6}$ molecules, and directional nonreciprocal coupling shielding entanglement-generating interactions from backaction noise. Unlike optical parametric amplifier schemes where vibration-vibration enhancement suppresses optical-vibration correlations, our $\mathcal{PT}$-symmetric architecture circumvents this fundamental trade-off, validated through rigorous stability analysis via Routh-Hurwitz criterion.

DOI
10.48550/arxiv.2509.16675

Related papers

Nonreciprocal entanglement in exciton optomechanics with an optical parametric amplifier

Zhen-Sen Lin, Rui Zhang, Zi-Wei Jiang +4 more

We study nonreciprocal bipartite and tripartite entanglement in a spinning exciton-optomechanical system (EOMS) with an optical parametric amplifier (OPA). We demonstrate that nonreciprocal entanglement among photons, excitons, and phonons can be achieved under experimentally feasible parameters. We find that the nonreciprocal entanglement induced by Sagnac effects can be regulated through the OPA. Particularly, We show that the OPA significantly enhances photon-exciton entanglement and tripartite entanglement but weakens photon-phonon and exciton-phonon entanglement. Moreover, we find that the photon-exciton nonreciprocal entanglement not only can be generated at room temperature and even higher temperature but also exhibits highly robustness to cavity dissipation. Our works open a way to manipulate the room-temperature nonreciprocal entanglement, which may be useful for developing nonreciprocal quantum technologies.

quant-pharXiv:2603.01397•Mar 3, 2026•0 citations

Quantum entanglement enhanced via dark mode control in molecular optomechanics

E. Kongkui Berinyuy, P. Djorwé, A. N. Al-Ahmadi +2 more

Quantum entanglement is an interesting resource for modern quantum technologies, where generating multiple quantum entanglement is highly required. However, entanglement engineering between multiple modes is strongly suppressed by dark mode effect. Here, we proposed a scheme based on molecular cavity optomechanical structure that enhances quantum bipartite and tripartite entanglement via dark mode breaking. Our proposal consists of an optical cavity that hosts two molecular ensembles which are coupled through an intermolecular coupling. A vibrational hopping rate $J_m$ captures the intermolecular coupling that is phase modulated via the synthetic gauge field method. The breaking of the dark mode is controlled by tuning both the intermolecular coupling and its modulation phase. By adjusting these parameters in our proposal, we can flexibly switch between the Dark Mode Unbroken (DMU) and the Dark Mode Broken (DMB) regimes. We find that in the dark-mode-unbroken regime, the amount of the generated bipartite and tripartite entanglement is significantly low or is suppressed. In contrast, in the dark-mode-broken regime, the entanglement is greatly enhanced,i.e., up to twofold enhancement. Moreover, the generated entanglement is more resilient against thermal noise in the dark-mode-broken regime compared to the thermal robustness in the unbroken regime. Therefore, our proposed scheme serves as a benckmark system to improve quantum correlations engineering, and to generate noise-tolerant quantum resources for applications in numerous modern quantum technologies.

quant-pharXiv:2602.14312•Feb 17, 2026•0 citations

Room-temperature exciton-vibration-photon entanglement in polariton optomechanics

Jian Huang, Zhedong Zhang

Room-temperature quantum entanglement not only is significant for the advancement of quantum physics but also has broad application prospects in quantum technology. Here we investigate the generation of room-temperature quantum entanglement in a polariton optomechanical system consisting of an optical mode, a molecular vibrational mode, and N excitonic modes. The excitons and vibration are coupled via conditional displacement interactions, while the photon-exciton couplings occur via electric dipole interactions. We find that, mediated by exciton-vibration interaction, strong entanglement is established between the photon and the exciton, as well as between the photon and the vibration. Notably, the photon-vibration entanglement exhibits an astonishing enhancement with an increasing number of excitons, even far surpassing the entanglement generated from direct coupling between the exciton and vibration. Moreover, we demonstrate that these entanglements not only can be generated in a room-temperature environment (T = 300 K) but also exhibit considerable robustness against thermal noise. Furthermore, we achieve tripartite entanglement in this system under both room- and ultrahigh-temperature conditions. The increase in the number of excitons can significantly improve the tolerance of tripartite entanglement to thermal noise and optical dissipation. Our results indicate that polariton optomechanical systems could provide a promising platform for generating room-temperature and high-temperature-resistant entangled quantum resources, which are crucial for practical quantum technologies. ©2025 American Physical Society

Physical Review A•Jun 17, 2025•5 citations

Generation and Enhancement of Bipartite and Tripartite Entanglement in an Electro-Optomechanical Ring Cavity

Fouad Essaadi, Yassine Oussarhan, Mohamed Ouhammou +4 more

This study investigates the generation and enhancement of quantum entanglement in an electro-optomechanical ring cavity system. The setup integrates two Coulomb-coupled mechanical resonators, which serve as the fundamental mechanism for the generation of bipartite and tripartite entanglement via charge mediated coupling. We then demonstrate the significant enhancement of this entanglement via a nonlinear parametric drive (an optical parametric amplifier, OPA), which injects a controllable nonlinearity into the cavity. We derive the system's Hamiltonian and the corresponding quantum Langevin equations, which are linearized around steady-state solutions to analyze Gaussian quantum fluctuations. Employing the covariance matrix formalism, we quantify bipartite entanglement via logarithmic negativity and tripartite entanglement via the minimum residual contangle. Our results unequivocally show that while the Coulomb interaction is indispensable for creating entanglement, the OPA acts as a powerful control tool, dramatically amplifying the degree of quantum correlations for all subsystems. We find that the strength of entanglement is highly sensitive to several parameters and can be optimized through the strategic selection of the OPA's gain and phase, the laser detuning, and the input power. A key finding is the existence of a trade-off, where parameters that maximize entanglement also constrain the stable operating regime of the system. Furthermore, thermal noise is shown to progressively degrade all quantum correlations, underscoring the necessity for low-temperature operation. These findings provide comprehensive guidance for parameter optimization, outlining a clear path from generation to enhancement, and highlight the potential of such hybrid systems as versatile platforms for controlling multipartite entanglement in quantum technologies.

quant-pharXiv:2608.03578•Aug 5, 2026•0 citations

Nonreciprocal coupling induced entanglement enhancement in a double-cavity optomechanical system

Yuan Yuan Liu, Zhi‐Ming Zhang, Jun‐Hao Liu +2 more

We investigate the quantum entanglement in a double-cavity optomechanical system consisting of an optomechanical cavity and an auxiliary cavity, where the optomechanical cavity mode couples with the mechanical mode via radiation-pressure interaction, and simultaneously couples with the auxiliary cavity mode via nonreciprocal coupling. We study the entanglement between the mechanical oscillator and the cavity modes when the two cavities are reciprocally or nonreciprocally coupled. The logarithmic negativity E n ( 1 ) ( E n ( 2 ) ) is adopted to describe the entanglement degree between the mechanical mode and the optomechanical cavity mode (the auxiliary cavity mode). We find that both E n ( 1 ) and E n ( 2 ) have maximum values in the case of reciprocal coupling. By using nonreciprocal coupling, E n ( 1 ) and E n ( 2 ) can exceed those maximum values, and a wider detuning region where the entanglement exists can be obtained. Moreover, the entanglement robustness with respect to the environment temperature is also effectively enhanced.

Chinese Physics B•Apr 6, 2022•9 citations

Nonreciprocal optomechanical entanglement in an asymmetric Fabry-Perot cavity

Jia-Kang Wu, Ning Hu, Jie-Qiao Liao +1 more

Nonreciprocal transmission (classical nonreciprocity) in optomechanical systems based on asymmetric Fabry-Perot (F-P) cavities has been theoretically proposed and experimentally demonstrated. However, nonreciprocal quantum effects, particularly nonreciprocal quantum entanglement, remain unexplored in such systems. Here, we propose to generate nonreciprocal optomechanical entanglement in an asymmetric F-P cavity and discuss the connection between the nonreciprocal transmission and nonreciprocal quantum entanglement. We reproduce the nonreciprocal transmission spectra by solving the quantum Langevin equations, and then discuss the optimal parameters to achieve nonreciprocal optomechanical entanglement in the system. We show that a greater and more robust optomechanical entanglement can be approached in the asymmetric F-P cavities, in comparing with the symmetric cavities. Furthermore, we find that the degrees of classical and quantum nonreciprocities do not exhibit positive correlation as expected. Our work shows that the classical and quantum nonreciprocities can be realized simultaneously in the asymmetric F-P cavities, which provide a platform to explore the connection between classical and quantum nonreciprocities.

quant-pharXiv:2606.06988•Jun 8, 2026•0 citations
Multipartite quantum entanglement in PT\mathcal{PT}PT-symmetric molecular optomechanics: Nonreciprocal enhancement and thermal resilience to \SI{500}{\kelvin}
We present a theoretical framework for a PT\mathcal{PT}PT-symmetric double-cavity molecular optomechanical system demonstrating nonreciprocal enhancement of multipartite quantum entanglement at elevated temperatures. All bipartite entanglement channels (EacE_{ac}Eac​, EaB1E_{aB_1}EaB1​​, EcB2E_{cB_2}EcB2​​, EB1B2E_{B_1B_2}EB1​B2​​) simultaneously maximize at optimal nonreciprocal asymmetry J1/J2≈5J_1/J_2 \approx 5J1​/J2​≈5, with entanglement persisting to T∼\SIrange400500\kelvinT \sim \SIrange{400}{500}{\kelvin}T∼\SIrange400500\kelvin (material-limited ceiling) two orders of magnitude beyond conventional optomechanical systems. This thermal resilience and balanced enhancement across all channels arise from synergistic combination of ultra-high-frequency molecular vibrations (ωm/2π=\SI30\tera\hertzω_m/2π= \SI{30}{\tera\hertz}ωm​/2π=\SI30\tera\hertz), collective N\sqrt{N}N​ coupling enhancement with N=\nume6N=\num{e6}N=\nume6 molecules, and directional nonreciprocal coupling shielding entanglement-generating interactions from backaction noise. Unlike optical parametric amplifier schemes where vibration-vibration enhancement suppresses optical-vibration correlations, our PT\mathcal{PT}PT-symmetric architecture circumvents this fundamental trade-off, validated through rigorous stability analysis via Routh-Hurwitz criterion.
We study nonreciprocal bipartite and tripartite entanglement in a spinning exciton-optomechanical system (EOMS) with an optical parametric amplifier (OPA). We demonstrate that nonreciprocal entanglement among photons, excitons, and phonons can be achieved under experimentally feasible parameters. We find that the nonreciprocal entanglement induced by Sagnac effects can be regulated through the OPA. Particularly, We show that the OPA significantly enhances photon-exciton entanglement and tripartite entanglement but weakens photon-phonon and exciton-phonon entanglement. Moreover, we find that the photon-exciton nonreciprocal entanglement not only can be generated at room temperature and even higher temperature but also exhibits highly robustness to cavity dissipation. Our works open a way to manipulate the room-temperature nonreciprocal entanglement, which may be useful for developing nonreciprocal quantum technologies.
Quantum entanglement is an interesting resource for modern quantum technologies, where generating multiple quantum entanglement is highly required. However, entanglement engineering between multiple modes is strongly suppressed by dark mode effect. Here, we proposed a scheme based on molecular cavity optomechanical structure that enhances quantum bipartite and tripartite entanglement via dark mode breaking. Our proposal consists of an optical cavity that hosts two molecular ensembles which are coupled through an intermolecular coupling. A vibrational hopping rate JmJ_mJm​ captures the intermolecular coupling that is phase modulated via the synthetic gauge field method. The breaking of the dark mode is controlled by tuning both the intermolecular coupling and its modulation phase. By adjusting these parameters in our proposal, we can flexibly switch between the Dark Mode Unbroken (DMU) and the Dark Mode Broken (DMB) regimes. We find that in the dark-mode-unbroken regime, the amount of the generated bipartite and tripartite entanglement is significantly low or is suppressed. In contrast, in the dark-mode-broken regime, the entanglement is greatly enhanced,i.e., up to twofold enhancement. Moreover, the generated entanglement is more resilient against thermal noise in the dark-mode-broken regime compared to the thermal robustness in the unbroken regime. Therefore, our proposed scheme serves as a benckmark system to improve quantum correlations engineering, and to generate noise-tolerant quantum resources for applications in numerous modern quantum technologies.
Room-temperature quantum entanglement not only is significant for the advancement of quantum physics but also has broad application prospects in quantum technology. Here we investigate the generation of room-temperature quantum entanglement in a polariton optomechanical system consisting of an optical mode, a molecular vibrational mode, and N excitonic modes. The excitons and vibration are coupled via conditional displacement interactions, while the photon-exciton couplings occur via electric dipole interactions. We find that, mediated by exciton-vibration interaction, strong entanglement is established between the photon and the exciton, as well as between the photon and the vibration. Notably, the photon-vibration entanglement exhibits an astonishing enhancement with an increasing number of excitons, even far surpassing the entanglement generated from direct coupling between the exciton and vibration. Moreover, we demonstrate that these entanglements not only can be generated in a room-temperature environment (T = 300 K) but also exhibit considerable robustness against thermal noise. Furthermore, we achieve tripartite entanglement in this system under both room- and ultrahigh-temperature conditions. The increase in the number of excitons can significantly improve the tolerance of tripartite entanglement to thermal noise and optical dissipation. Our results indicate that polariton optomechanical systems could provide a promising platform for generating room-temperature and high-temperature-resistant entangled quantum resources, which are crucial for practical quantum technologies. ©2025 American Physical Society
This study investigates the generation and enhancement of quantum entanglement in an electro-optomechanical ring cavity system. The setup integrates two Coulomb-coupled mechanical resonators, which serve as the fundamental mechanism for the generation of bipartite and tripartite entanglement via charge mediated coupling. We then demonstrate the significant enhancement of this entanglement via a nonlinear parametric drive (an optical parametric amplifier, OPA), which injects a controllable nonlinearity into the cavity. We derive the system's Hamiltonian and the corresponding quantum Langevin equations, which are linearized around steady-state solutions to analyze Gaussian quantum fluctuations. Employing the covariance matrix formalism, we quantify bipartite entanglement via logarithmic negativity and tripartite entanglement via the minimum residual contangle. Our results unequivocally show that while the Coulomb interaction is indispensable for creating entanglement, the OPA acts as a powerful control tool, dramatically amplifying the degree of quantum correlations for all subsystems. We find that the strength of entanglement is highly sensitive to several parameters and can be optimized through the strategic selection of the OPA's gain and phase, the laser detuning, and the input power. A key finding is the existence of a trade-off, where parameters that maximize entanglement also constrain the stable operating regime of the system. Furthermore, thermal noise is shown to progressively degrade all quantum correlations, underscoring the necessity for low-temperature operation. These findings provide comprehensive guidance for parameter optimization, outlining a clear path from generation to enhancement, and highlight the potential of such hybrid systems as versatile platforms for controlling multipartite entanglement in quantum technologies.
We investigate the quantum entanglement in a double-cavity optomechanical system consisting of an optomechanical cavity and an auxiliary cavity, where the optomechanical cavity mode couples with the mechanical mode via radiation-pressure interaction, and simultaneously couples with the auxiliary cavity mode via nonreciprocal coupling. We study the entanglement between the mechanical oscillator and the cavity modes when the two cavities are reciprocally or nonreciprocally coupled. The logarithmic negativity E n ( 1 ) ( E n ( 2 ) ) is adopted to describe the entanglement degree between the mechanical mode and the optomechanical cavity mode (the auxiliary cavity mode). We find that both E n ( 1 ) and E n ( 2 ) have maximum values in the case of reciprocal coupling. By using nonreciprocal coupling, E n ( 1 ) and E n ( 2 ) can exceed those maximum values, and a wider detuning region where the entanglement exists can be obtained. Moreover, the entanglement robustness with respect to the environment temperature is also effectively enhanced.
Nonreciprocal transmission (classical nonreciprocity) in optomechanical systems based on asymmetric Fabry-Perot (F-P) cavities has been theoretically proposed and experimentally demonstrated. However, nonreciprocal quantum effects, particularly nonreciprocal quantum entanglement, remain unexplored in such systems. Here, we propose to generate nonreciprocal optomechanical entanglement in an asymmetric F-P cavity and discuss the connection between the nonreciprocal transmission and nonreciprocal quantum entanglement. We reproduce the nonreciprocal transmission spectra by solving the quantum Langevin equations, and then discuss the optimal parameters to achieve nonreciprocal optomechanical entanglement in the system. We show that a greater and more robust optomechanical entanglement can be approached in the asymmetric F-P cavities, in comparing with the symmetric cavities. Furthermore, we find that the degrees of classical and quantum nonreciprocities do not exhibit positive correlation as expected. Our work shows that the classical and quantum nonreciprocities can be realized simultaneously in the asymmetric F-P cavities, which provide a platform to explore the connection between classical and quantum nonreciprocities.