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:2311.18229

Direct Manipulation of quantum entanglement from the non-Hermitian nature of light-matter interaction

Kangkang Li, Yin Cai, Yan Jin, Feng Zhou, Liu, Fu, Lei Zhang, Feng Li, Yanpeng Zhang

Published Nov 30, 2023• 0 citations
arXivHTMLPDF

Abstract

Biphoton process is an essential benchmark for quantum information science and technologies, while great efforts have been made to improve the coherence of the system for better quantum correlations. Nevertheless, we find that the non-Hermitian features induced by the atomic quantum interference could be well employed for the direct control of entanglement. We report the demonstration of exceptional point (EP) in biphotons by measuring the light-atom interaction as a natural non-Hermitian system, in which the electromagnetically induced transparency regime provides a powerful mechanism to precisely tune the non-Hermitian coupling strength. Such biphoton correlation is tuned within an unprecedented large range from Rabi oscillation to antibunching-exponential-decay, also indicating high-dimensional entanglement within the strong and weak light-matter coupling regimes. The EP at the transition point between the two regimes is clearly observed with the biphoton quantum correlation measurements, exhibiting a single exponential decay and manifesting the coalesced single eigenstate. Our results provide a unique method to realize the controllability of natural non-Hermitian processes without the assistance of artificial photonic structures, and paves the way for quantum control by manipulating the non-Hermitian features of the light-matter interaction.

DOI
10.48550/arxiv.2311.18229

Related papers

Direct Manipulation of Biphoton Generation From the non‐Hermitian Nature of Light‐matter Interaction

Kangkang Li, Yin Cai, Jin Yan +5 more

Abstract While biphoton generation holds significant importance in quantum entanglement and quantum technology, its dynamics involving non‐Hermitian characteristics have experimentally been untouched so far. Nevertheless, it is found that the non‐Hermitian features induced by the atomic coherence can be well employed for the direct control of biphoton generation and entanglement. By harnessing such natural non‐Hermitian interaction, a method is devised to expand a non‐Hermitian Hao biphoton generation processes. It is experimentally demonstrated such biphoton correlation can be adjusted within an unprecedentedly wide range, ranging from Rabi oscillation to antibunching‐exponential‐decay. Typically, the exceptional point at the transition boundary between the two regimes is distinctly observed.

Laser & Photonics Review•Feb 27, 2025•8 citations

Multipartite entanglement generation with high-order non-Hermitian exceptional points from dressing-controlled atomic nonlinearity

Yan Jin, Lifan Chen, Zhan Zheng +6 more

Multipartite entanglement has emerged as a valuable quantum resource for constructing large-scale quantum networks. However, the presence of non-Hermitian features induced by natural microscopic quantum systems significantly modifies the overall response of nonlinear parametric processes, thereby enabling direct manipulation of multipartite entanglement properties. In this study, we demonstrate the generation of multimode entanglement through atomic four-wave mixing (FWM) and analyze the properties of exceptional points (EP) under dressing control in non-Hermitian systems. By leveraging dressing-controlled atomic nonlinearity, we achieve versatile EPs and higher-order EPs by carefully tuning the atomic multi-parameter in the cascading FWM system. Additionally, we investigate the entanglement properties of various permutations of the output signal modes using the positive partial transpose (PPT) criterion. Notably, under non-Hermitian control, the application of single-, double-, and N-dressing splits leads to coherent multichannel control and further extends the scale of quantum entanglement. The outcomes of our research offer a novel approach to actively control non-Hermitian quantum phenomena without relying on artificial photonic structures. Furthermore, this paves the way for the realization of complex quantum information tasks by exploiting the non-Hermitian characteristics of the light-matter interaction.

Optics Express•Nov 13, 2023•4 citations

Natural Non-Hermitian Control of High-Dimensional Rabi Oscillating of Tri-photon Using Multi-dressing Quantization

Jiaxuan Wei, Qinyue Yang, Jiajia Wei +8 more

Abstract Non-Hermitian degeneracies, also known as exceptional points, have recently emerged as a new way to engineer the response of open physical systems, we construct non-Hermitian systems through atomic electromagnetically induced transparency structures, based on which we study energy-level high-dimensional quantized photon correlations under dressing field induced parity-time (PT) symmetry and symmetry breaking. We study the symmetry breaking through exceptional point (EP) control in dressing-controlled energy-level process is natural EP, which are born to be non-Hermitian without artificial photonic structures. When the dressing Rabi frequency (de-phase rate) dominates, the real part (imaginary part) splits, and leads to in-phase (out-of-phase) constructive (destructive) dressing quantization. It can also be used to develop atomic-like symmetry-breaking photonic chips and pseudo-spin devices in the future.

•Mar 13, 2024•1 citation

Regulation of non-Hermitian couplings in a spontaneous six-wave mixing process

Zhou Feng, Rui Zhuang, Haitian Tang +5 more

Non-Hermitian quantum systems — characterized by parity–time symmetry and the emergence of exceptional points — have attracted increasing interest, particularly in light–matter interaction platforms where dissipation and radiative losses play a fundamental role. In this work, we investigate the modulation of coupling states between atomic energy levels during the generation of backward W-state triphotons via a spontaneous six-wave mixing (SSWM) process. By employing tunable external control beams, we realize dynamic modulation from the weak to the strong coupling regime, accompanied by a qualitative transition in triphoton coincidence statistics from anti-bunching to damped Rabi oscillations. Remarkably, the appearance of single exponential decays in the triphoton coincidence count traces marks the onset of an exceptional point in the non-Hermitian system. Furthermore, triphoton correlations in the τ21 and τ31 directions can be independently modulated by selectively tuning of the coupling state via ED1 and ED2, respectively. These results provide a versatile and coherent platform for the one-step generation of backward entangled triphoton states and offer a promising approach to engineering high-dimensional entanglement, with potential applications in quantum communication and quantum information processing.

Frontiers of Physics•Jan 1, 2026•1 citation

Nanoparticle-mediated controlled entanglement based on non-Hermitian coupling

Zhonghui Yuan, Zhang Geng, Yongjian Chen +3 more

We propose a method to achieve a coherent switch of optomagnonic entanglement in a cavity optomagnonic system with non-Hermitian coupling. The strength of photon-photon and photon-magnon entanglement can be controlled by tuning the relative phase angle of two nanoparticles and optimizing the detuning of two optical modes. We show that the bipartite entanglement is significantly enhanced by selecting a suitable optomagnonics coupling strength in the presence of the exceptional points (EPs). The relative phase not only enhances the entanglement strength but also increases the entanglement domain over a wide range of detuning compared to the Hermitian system. By manipulating the system toward or away from EPs, versatile tunability of the tripartite entanglement, mean photon, and magnon numbers can be achieved. Additionally, the direction of asymmetric transmission can also be well tuned in a highly asymmetric way via non-Hermitian coupling. The study of controlled entanglement may provide the theoretical basis and reference for the research and development of new tunable quantum devices.

Physical Review A•Aug 27, 2024•4 citations

Non-Hermitian control of reconfigurable backward time-energy-entangled W triphotons

Zhou Feng, Rui Zhuang, Haitian Tang +5 more

The generation and control of quantum entangled states hold significant importance for quantum information processing. Non-Hermitian systems, characterized by parity-time symmetry and exceptional points, provide a powerful framework for controlling quantum states. Although both the non-Hermitian nature and triphoton generation have been demonstrated in light–matter interaction processes, achieving non-Hermitian control of triphoton states remains challenging because of the lack of active adjustment within a wide range of coupling strengths. We realize the non-Hermitian control of reconfigurable backward time-energy-entangled W triphotons through atomic coherence, transiting the different eigenstates of the triphoton by employing external control beams. These different triphoton eigenstates are experimentally demonstrated by the triphoton temporal correlations, ranging from Rabi oscillation to antibunching exponential decay. Furthermore, both the generation rate and the violation of the Cauchy–Schwarz inequality of triphotons confirm the highly nonclassical performance. Our results establish a versatile platform for reconfigurable multipartite entanglement and provide new opportunities for complex quantum information processing based on non-Hermitian light–matter interactions.

Advanced Photonics Nexus•Jul 22, 2026•0 citations
Biphoton process is an essential benchmark for quantum information science and technologies, while great efforts have been made to improve the coherence of the system for better quantum correlations. Nevertheless, we find that the non-Hermitian features induced by the atomic quantum interference could be well employed for the direct control of entanglement. We report the demonstration of exceptional point (EP) in biphotons by measuring the light-atom interaction as a natural non-Hermitian system, in which the electromagnetically induced transparency regime provides a powerful mechanism to precisely tune the non-Hermitian coupling strength. Such biphoton correlation is tuned within an unprecedented large range from Rabi oscillation to antibunching-exponential-decay, also indicating high-dimensional entanglement within the strong and weak light-matter coupling regimes. The EP at the transition point between the two regimes is clearly observed with the biphoton quantum correlation measurements, exhibiting a single exponential decay and manifesting the coalesced single eigenstate. Our results provide a unique method to realize the controllability of natural non-Hermitian processes without the assistance of artificial photonic structures, and paves the way for quantum control by manipulating the non-Hermitian features of the light-matter interaction.
Abstract While biphoton generation holds significant importance in quantum entanglement and quantum technology, its dynamics involving non‐Hermitian characteristics have experimentally been untouched so far. Nevertheless, it is found that the non‐Hermitian features induced by the atomic coherence can be well employed for the direct control of biphoton generation and entanglement. By harnessing such natural non‐Hermitian interaction, a method is devised to expand a non‐Hermitian Hao biphoton generation processes. It is experimentally demonstrated such biphoton correlation can be adjusted within an unprecedentedly wide range, ranging from Rabi oscillation to antibunching‐exponential‐decay. Typically, the exceptional point at the transition boundary between the two regimes is distinctly observed.
Multipartite entanglement has emerged as a valuable quantum resource for constructing large-scale quantum networks. However, the presence of non-Hermitian features induced by natural microscopic quantum systems significantly modifies the overall response of nonlinear parametric processes, thereby enabling direct manipulation of multipartite entanglement properties. In this study, we demonstrate the generation of multimode entanglement through atomic four-wave mixing (FWM) and analyze the properties of exceptional points (EP) under dressing control in non-Hermitian systems. By leveraging dressing-controlled atomic nonlinearity, we achieve versatile EPs and higher-order EPs by carefully tuning the atomic multi-parameter in the cascading FWM system. Additionally, we investigate the entanglement properties of various permutations of the output signal modes using the positive partial transpose (PPT) criterion. Notably, under non-Hermitian control, the application of single-, double-, and N-dressing splits leads to coherent multichannel control and further extends the scale of quantum entanglement. The outcomes of our research offer a novel approach to actively control non-Hermitian quantum phenomena without relying on artificial photonic structures. Furthermore, this paves the way for the realization of complex quantum information tasks by exploiting the non-Hermitian characteristics of the light-matter interaction.
Abstract Non-Hermitian degeneracies, also known as exceptional points, have recently emerged as a new way to engineer the response of open physical systems, we construct non-Hermitian systems through atomic electromagnetically induced transparency structures, based on which we study energy-level high-dimensional quantized photon correlations under dressing field induced parity-time (PT) symmetry and symmetry breaking. We study the symmetry breaking through exceptional point (EP) control in dressing-controlled energy-level process is natural EP, which are born to be non-Hermitian without artificial photonic structures. When the dressing Rabi frequency (de-phase rate) dominates, the real part (imaginary part) splits, and leads to in-phase (out-of-phase) constructive (destructive) dressing quantization. It can also be used to develop atomic-like symmetry-breaking photonic chips and pseudo-spin devices in the future.
Non-Hermitian quantum systems — characterized by parity–time symmetry and the emergence of exceptional points — have attracted increasing interest, particularly in light–matter interaction platforms where dissipation and radiative losses play a fundamental role. In this work, we investigate the modulation of coupling states between atomic energy levels during the generation of backward W-state triphotons via a spontaneous six-wave mixing (SSWM) process. By employing tunable external control beams, we realize dynamic modulation from the weak to the strong coupling regime, accompanied by a qualitative transition in triphoton coincidence statistics from anti-bunching to damped Rabi oscillations. Remarkably, the appearance of single exponential decays in the triphoton coincidence count traces marks the onset of an exceptional point in the non-Hermitian system. Furthermore, triphoton correlations in the τ21 and τ31 directions can be independently modulated by selectively tuning of the coupling state via ED1 and ED2, respectively. These results provide a versatile and coherent platform for the one-step generation of backward entangled triphoton states and offer a promising approach to engineering high-dimensional entanglement, with potential applications in quantum communication and quantum information processing.
We propose a method to achieve a coherent switch of optomagnonic entanglement in a cavity optomagnonic system with non-Hermitian coupling. The strength of photon-photon and photon-magnon entanglement can be controlled by tuning the relative phase angle of two nanoparticles and optimizing the detuning of two optical modes. We show that the bipartite entanglement is significantly enhanced by selecting a suitable optomagnonics coupling strength in the presence of the exceptional points (EPs). The relative phase not only enhances the entanglement strength but also increases the entanglement domain over a wide range of detuning compared to the Hermitian system. By manipulating the system toward or away from EPs, versatile tunability of the tripartite entanglement, mean photon, and magnon numbers can be achieved. Additionally, the direction of asymmetric transmission can also be well tuned in a highly asymmetric way via non-Hermitian coupling. The study of controlled entanglement may provide the theoretical basis and reference for the research and development of new tunable quantum devices.
The generation and control of quantum entangled states hold significant importance for quantum information processing. Non-Hermitian systems, characterized by parity-time symmetry and exceptional points, provide a powerful framework for controlling quantum states. Although both the non-Hermitian nature and triphoton generation have been demonstrated in light–matter interaction processes, achieving non-Hermitian control of triphoton states remains challenging because of the lack of active adjustment within a wide range of coupling strengths. We realize the non-Hermitian control of reconfigurable backward time-energy-entangled W triphotons through atomic coherence, transiting the different eigenstates of the triphoton by employing external control beams. These different triphoton eigenstates are experimentally demonstrated by the triphoton temporal correlations, ranging from Rabi oscillation to antibunching exponential decay. Furthermore, both the generation rate and the violation of the Cauchy–Schwarz inequality of triphotons confirm the highly nonclassical performance. Our results establish a versatile platform for reconfigurable multipartite entanglement and provide new opportunities for complex quantum information processing based on non-Hermitian light–matter interactions.