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:2410.21122

Quantum entanglement and Einstein-Podolsky-Rosen steering in magnon frequency comb

Qianjun Zheng, H. Y. Yuan, Yunshan Cao, Peng Yan

Published Oct 28, 2024• 0 citations
arXivHTMLPDF

Abstract

Significant progress has been made for the emerging concept of magnon frequency comb (MFC) but mainly in the classical region. The quantum property of the comb structure is yet to be explored. Here we theoretically investigate the quantum fluctuations of frequency combs and demonstrate the continuous-variable quantum entanglement and Einstein-Podolsky-Rosen (EPR) steering between different teeth of MFC. Without loss of generality, we address this issue in a hybrid magnon-skyrmion system. We observe a strong two-mode squeezed entanglement and asymmetric steering between the sum- and difference-frequency magnon teeth mediated by the skyrmion that acts as an effective reservoir to cool the Bogoliubov mode delocalized over the first-order magnon pair in MFC. Our findings show the prominent quantum nature of MFC, which has the potential to be utilized in ultrafast quantum metrology and multi-task quantum information processing.

DOI
10.48550/arxiv.2410.21122

Related papers

Multipartite entanglement and one-way steering in magnon frequency comb

Qianjun Zheng, Yunshan Cao, Peng Yan

Abstract We theoretically demonstrate that multipartite entanglement and one-way Einstein–Podolsky–Rosen (EPR) steering in a magnon frequency comb (MFC) can be generated in a hybrid magnon–skyrmion system. When the system is driven by two microwave fields at the magnonic whispering gallery mode (mWGM) and the skyrmion, the skyrmion can be simultaneously entangled with three magnon modes of the MFC and the entanglement of the first-order magnon pair in the MFC also appears. The results show that the perfect one-way steering between the skyrmion and the three magnons can be obtained. Interestingly, the steering direction can be manipulated by controlling the amplitudes of two drive fields, which provides flexibility in controlling the asymmetry of the EPR steering and may well have practical applications. Moreover, the genuine tripartite entanglement among the skyrmion and the first-order magnon pair can be achieved with appropriate parameters in the steady state. Our work exhibits that the MFC has great potential in preparing multi-mode entanglement resources, with promising applications in quantum communication.

Chinese Physics B•Aug 11, 2025•1 citation

Remote asymmetric Einstein-Podolsky-Rosen steering of magnons via a single pathway of Bogoliubov dissipation

Deyi Kong, Jun Xu, Ya Tian +2 more

We propose a scheme to generate remote asymmetric Einstein-Podolsky-Rosen (EPR) steering of two magnon modes in a hybrid ferromagnet-superconductor system. In our scheme, the indirect coherent coupling between two distant magnons and a $\mathrm{\ensuremath{\Delta}}$-type superconducting atom is established via exchange of virtual photons in two dispersive cavities. As a consequence, the artificial atom acting as a reservoir can produce asymmetrical magnon-magnon steering via a single dissipation channel. Interestingly, we find that the steering directivity is determined by cooling either Bogoliubov mode selectively rather than increasing the extra noise as in conventional schemes. This provides a novel idea to prepare remote EPR steering in solid devices, which may find potential applications in quantum information processing.

Physical Review Research•Feb 2, 2022•37 citations

Magnon-magnon entanglement and its quantification via a microwave cavity

Vahid Azimi Mousolou, Yuefei Liu, Anders Bergman +5 more

Quantum magnonics is an emerging research field, with great potential for applications in magnon based hybrid systems and quantum information processing. Quantum correlation, such as entanglement, is a central resource in many quantum information protocols that naturally comes about in any study toward quantum technologies. This applies also to quantum magnonics. Here, we investigate antiferromagnetic coupling of two ferromagnetic sublattices that can have two different magnon modes. We show how this may lead to experimentally measurable bipartite continuous-variable magnon-magnon entanglement. The entanglement can be fully characterized via a single squeezing parameter or, equivalently, entanglement parameter. The clear relation between the entanglement parameter and the Einstein, Podolsky, and Rosen (EPR) function of the ground state opens up for experimental quantification magnon-magnon continuous-variable entanglement and EPR nonlocality. We propose a practical experimental realization to measure the EPR function of the ground state, in a setting that relies on magnon-photon interaction in a microwave cavity.

arXiv:2106.06862•Physical review. B./Physical review. B•Dec 8, 2021•45 citations

Quantum entanglement and Einstein-Podolsky-Rosen steering in ultrastrongly light-matter-coupled systems

Yu‐qiang Liu, Shan Sun, Yi‐jia Yang +5 more

This work presents a scheme for engineering quantum entanglement and Einstein-Podolsky-Rosen (EPR) steering with Gaussian measurements based on the quantum Hopfield model that incorporates a common thermal reservoir. We begin by examining quantum correlations, specifically quantum entanglement and EPR steering, in the ground state. These quantum correlations primarily stem from squeezing interactions in weak-coupling and normal strong-coupling regimes. As the coupling strength increases, especially upon entering the ultrastrong-coupling regime, the correlations emerge from the combined effect of squeezing and mix-mode interactions. Importantly, this scenario enables the realization of two-way EPR steering. Moreover, lower optical frequencies enhance both quantum entanglement and EPR steering. Further, when considering thermal effects, the ultrastrong-coupling and deep strong-coupling regimes, paired with lower optical frequencies, lead to improved entanglement. The one-way EPR steering for the resonant case can be effectively controlled in the ultrastrong-coupling and deep strong-coupling regimes which originate from the asymmetry of the subsystem and reservoir coupling induced by the diamagnetic term. Additionally, one-way EPR steering can also be produced for the nonresonant case. In this case, the asymmetry of the subsystem and reservoir originates from the combined effect of nonresonant frequencies and the diamagnetic term. Our findings have the potential to inspire further research into quantum information processing that leverages light-matter entanglement and EPR steering.

arXiv:2505.08188•Physical Review A•May 19, 2025•1 citation

Quantum entanglement and Einstein-Podolsky-Rosen steering in a magnon frequency comb

Qianjun Zheng, H. Y. Yuan, Yunshan Cao +1 more

Physical review. B./Physical review. B•Jun 9, 2025•4 citations

One-way Einstein-Podolsky-Rosen steering via atomic coherence

Wenxue Zhong, Guangling Cheng, Xiangming Hu

We explore the asymmetric Einstein-Podolsky-Rosen (EPR) steering of field modes via atomic coherent effects. A resonant four-level system in double-cascade configuration is under our consideration, where the atoms are excited by the applied fields from one cascade channel and two cavity modes are generated from the other cascade transition. The results show two cavity modes are suitable for achieving the steady-state one-way EPR steering. We analyze the physics in terms of the dressed-atom Bogoliubov-field-mode approach. It is found that one of two Bogoliubov modes is mediated by the resonant coupling of the dressed atoms and the other is decoupled from them. This leads to the so-called one-channel dissipation, by which the dressed atoms absorb the average excitations from one transformed mode and then two original modes are pulled into the asymmetric correlation. Remarkably, the present scheme is focused on the full-resonant interaction not only between the classical fields, the cavity modes and the bare atoms, but also between the Bogoliubov modes and dressed atoms, which will induce the one-way steering simply via adjusting the intensity of an external field. Furthermore, the EPR steering could occur between the field modes with the large frequency difference, such as optical and microwave fields, which is more useful for the practical quantum communication. Based on the one-channel dissipation, the obtainable one-way EPR steering is rather against the dynamic fluctuations and is regardless of the initial state.

Optics Express•May 2, 2017•27 citations
Significant progress has been made for the emerging concept of magnon frequency comb (MFC) but mainly in the classical region. The quantum property of the comb structure is yet to be explored. Here we theoretically investigate the quantum fluctuations of frequency combs and demonstrate the continuous-variable quantum entanglement and Einstein-Podolsky-Rosen (EPR) steering between different teeth of MFC. Without loss of generality, we address this issue in a hybrid magnon-skyrmion system. We observe a strong two-mode squeezed entanglement and asymmetric steering between the sum- and difference-frequency magnon teeth mediated by the skyrmion that acts as an effective reservoir to cool the Bogoliubov mode delocalized over the first-order magnon pair in MFC. Our findings show the prominent quantum nature of MFC, which has the potential to be utilized in ultrafast quantum metrology and multi-task quantum information processing.
Abstract We theoretically demonstrate that multipartite entanglement and one-way Einstein–Podolsky–Rosen (EPR) steering in a magnon frequency comb (MFC) can be generated in a hybrid magnon–skyrmion system. When the system is driven by two microwave fields at the magnonic whispering gallery mode (mWGM) and the skyrmion, the skyrmion can be simultaneously entangled with three magnon modes of the MFC and the entanglement of the first-order magnon pair in the MFC also appears. The results show that the perfect one-way steering between the skyrmion and the three magnons can be obtained. Interestingly, the steering direction can be manipulated by controlling the amplitudes of two drive fields, which provides flexibility in controlling the asymmetry of the EPR steering and may well have practical applications. Moreover, the genuine tripartite entanglement among the skyrmion and the first-order magnon pair can be achieved with appropriate parameters in the steady state. Our work exhibits that the MFC has great potential in preparing multi-mode entanglement resources, with promising applications in quantum communication.
We propose a scheme to generate remote asymmetric Einstein-Podolsky-Rosen (EPR) steering of two magnon modes in a hybrid ferromagnet-superconductor system. In our scheme, the indirect coherent coupling between two distant magnons and a $\mathrm{\ensuremath{\Delta}}$-type superconducting atom is established via exchange of virtual photons in two dispersive cavities. As a consequence, the artificial atom acting as a reservoir can produce asymmetrical magnon-magnon steering via a single dissipation channel. Interestingly, we find that the steering directivity is determined by cooling either Bogoliubov mode selectively rather than increasing the extra noise as in conventional schemes. This provides a novel idea to prepare remote EPR steering in solid devices, which may find potential applications in quantum information processing.
Quantum magnonics is an emerging research field, with great potential for applications in magnon based hybrid systems and quantum information processing. Quantum correlation, such as entanglement, is a central resource in many quantum information protocols that naturally comes about in any study toward quantum technologies. This applies also to quantum magnonics. Here, we investigate antiferromagnetic coupling of two ferromagnetic sublattices that can have two different magnon modes. We show how this may lead to experimentally measurable bipartite continuous-variable magnon-magnon entanglement. The entanglement can be fully characterized via a single squeezing parameter or, equivalently, entanglement parameter. The clear relation between the entanglement parameter and the Einstein, Podolsky, and Rosen (EPR) function of the ground state opens up for experimental quantification magnon-magnon continuous-variable entanglement and EPR nonlocality. We propose a practical experimental realization to measure the EPR function of the ground state, in a setting that relies on magnon-photon interaction in a microwave cavity.
This work presents a scheme for engineering quantum entanglement and Einstein-Podolsky-Rosen (EPR) steering with Gaussian measurements based on the quantum Hopfield model that incorporates a common thermal reservoir. We begin by examining quantum correlations, specifically quantum entanglement and EPR steering, in the ground state. These quantum correlations primarily stem from squeezing interactions in weak-coupling and normal strong-coupling regimes. As the coupling strength increases, especially upon entering the ultrastrong-coupling regime, the correlations emerge from the combined effect of squeezing and mix-mode interactions. Importantly, this scenario enables the realization of two-way EPR steering. Moreover, lower optical frequencies enhance both quantum entanglement and EPR steering. Further, when considering thermal effects, the ultrastrong-coupling and deep strong-coupling regimes, paired with lower optical frequencies, lead to improved entanglement. The one-way EPR steering for the resonant case can be effectively controlled in the ultrastrong-coupling and deep strong-coupling regimes which originate from the asymmetry of the subsystem and reservoir coupling induced by the diamagnetic term. Additionally, one-way EPR steering can also be produced for the nonresonant case. In this case, the asymmetry of the subsystem and reservoir originates from the combined effect of nonresonant frequencies and the diamagnetic term. Our findings have the potential to inspire further research into quantum information processing that leverages light-matter entanglement and EPR steering.
We explore the asymmetric Einstein-Podolsky-Rosen (EPR) steering of field modes via atomic coherent effects. A resonant four-level system in double-cascade configuration is under our consideration, where the atoms are excited by the applied fields from one cascade channel and two cavity modes are generated from the other cascade transition. The results show two cavity modes are suitable for achieving the steady-state one-way EPR steering. We analyze the physics in terms of the dressed-atom Bogoliubov-field-mode approach. It is found that one of two Bogoliubov modes is mediated by the resonant coupling of the dressed atoms and the other is decoupled from them. This leads to the so-called one-channel dissipation, by which the dressed atoms absorb the average excitations from one transformed mode and then two original modes are pulled into the asymmetric correlation. Remarkably, the present scheme is focused on the full-resonant interaction not only between the classical fields, the cavity modes and the bare atoms, but also between the Bogoliubov modes and dressed atoms, which will induce the one-way steering simply via adjusting the intensity of an external field. Furthermore, the EPR steering could occur between the field modes with the large frequency difference, such as optical and microwave fields, which is more useful for the practical quantum communication. Based on the one-channel dissipation, the obtainable one-way EPR steering is rather against the dynamic fluctuations and is regardless of the initial state.