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

Physical Review Letters

Orbital-Angular-Momentum Multiplexed Continuous-Variable Entanglement from Four-Wave Mixing in Hot Atomic Vapor

Xiaozhou Pan, Shengkai Yu, Yanfen Zhou, Kun Zhang, Kai Zhang, Shuchao Lv, Sijin Li, Wei Wang, Jietai Jing

Published Aug 16, 2019• 126 citations
Publisher

Abstract

Multiplexing is crucial for the data-carrying capacity of information communication systems. Orbital angular momentum (OAM) with a topological charge $\ensuremath{\ell}$ ($\ensuremath{\ell}$ integer) provides a degree of freedom to realize multiplexing. In this Letter, we report an experimental implementation of OAM multiplexed continuous variables (CV) entanglement based on a four-wave mixing (FWM) process, in which 13 pairs of entangled Laguerre-Gauss (LG) modes, ${\mathrm{LG}}_{\ensuremath{\ell},\mathrm{pr}}$ and ${\mathrm{LG}}_{\ensuremath{-}\ensuremath{\ell},\mathrm{conj}}$, are simultaneously and deterministically generated, where $\ensuremath{\ell}$ ($\ensuremath{\ell}$ integer) is the topological charge corresponding to the OAM mode and pr (conj) indicates a probe (conjugate) beam. In the meanwhile, we experimentally show that there is no entanglement between the modes of ${\mathrm{LG}}_{\ensuremath{\ell},\mathrm{pr}}$ and ${\mathrm{LG}}_{\ensuremath{\ell},\mathrm{conj}}$ ($\ensuremath{\ell}\ensuremath{\ne}0$). These results clearly confirm the conservation of OAM in the FWM process from the viewpoint of a CV system. In addition, we investigate the entanglement properties of three types of coherent superposition of OAM modes. In the end, we also study the effect of the pump beam radius on the number of OAM multiplexing. Such OAM multiplexed CV entanglement provides a new perspective and platform to study CV quantum information protocols.

DOI
10.1103/physrevlett.123.070506

Related papers

Deterministic Generation of Orbital-Angular-Momentum Multiplexed Tripartite Entanglement

Sijin Li, Xiaozhou Pan, Yuan Ren +3 more

We demonstrate the experimental generation of orbital angular momentum (OAM) multiplexed multipartite entanglement with cascaded four-wave mixing processes in a continuous variable (CV) system. In particular, we implement the simultaneous generation of 9 sets of OAM multiplexed tripartite entanglement over 27 Laguerre-Gauss (LG) modes, as well as 20 sets of OAM multiplexed bipartite entanglement over 40 LG modes, which show the rich entanglement structure of the system. In addition, we also generate tripartite entanglement of three types of coherent OAM superposition modes. Such OAM multiplexed multipartite entanglement opens the avenue to construct CV parallel quantum network for realizing parallel quantum information protocols.

Physical Review Letters•Feb 28, 2020•108 citations

Experimental demonstration of complex four-wave mixing processes with pump of orbital-angular-momentum superposition mode

Xiaozhou Pan, Shengkai Yu, Kai Zhang +1 more

Orbital angular momentum (OAM), characterized by a topological charge ℓ (ℓ integer), serves as a promising vehicle for carrying quantum information. Generating a nonclassical field involving two or more OAM modes can largely enhance the data-carrying capacity of quantum information processing. In this Letter, we present the implementation of a four-wave mixing (FWM) process, featuring a pump beam of a coherent OAM superposition mode and a probe beam of a single OAM mode. We generate twin beams encompassing multiple OAM modes and illustrate their quantum correlation when the pump beam assumes different coherent OAM superposition modes. Furthermore, we analyze the OAM mode components in each output field to deepen our understanding of the nonlinear interaction among different OAM modes. The obtained results show the rich structure of the nonlinear interaction of OAM modes in the FWM process and provide a perspective to study quantum information protocols.

Applied Physics Letters•Apr 15, 2024•1 citation

Orbital-angular-momentum spectrum characterization of continuous-variable entanglement via the phase-shift interferometry

Rong Ma, Xiaoqin Qu, xiaowei wu +4 more

In addition to carrying spin angular momentum (SAM), light can also possess orbital angular momentum (OAM), whose quantum number can, in principle, take any integer value. This property provides a new degree of freedom to expand the capacity of both classical and quantum information. In recent years, generating OAM multiplexed continuous-variable entanglement via four-wave mixing (FWM) has emerged as an effective approach to increasing the capacity of quantum information channels. Consequently, there is a growing demand for precise characterization of the OAM spectrum in such quantum beams. Here we present, to the best of our knowledge, the first experimental demonstration of OAM spectrum measurement in quantum optics using phase-shifting interferometry (PSI). This method enables accurate characterization of the OAM spectrum of both the probe and conjugate beams in OAM multiplexed continuous-variable entanglement generated via the FWM process. These results provide an experimental foundation for the reliable detection and utilization of multiplexed OAM degrees of freedom in quantum communication and quantum information processing.

Optics Express•Jan 30, 2026•0 citations

Enhancing and flattening multiplexed quantum entanglement by utilizing perfect vortex modes

Qiwu Hu, Xutong Wang, Rui Zhang +3 more

We experimentally demonstrate a method for enhancing and flattening multiplexed entanglement in the four-wave mixing (FWM) process, which is implemented by replacing Laguerre-Gaussian (LG) modes with perfect vortex (PV) modes. For the topological charge l ranging from -5 to 5, the entanglement degrees of orbital angular momentum (OAM) multiplexed entanglement with PV modes are all larger than those of OAM multiplexed entanglement with LG modes. More importantly, for OAM multiplexed entanglement with PV modes, the degree of entanglement almost does not change with the topology value. In other words, we experimentally flatten the OAM multiplexed entanglement, which cannot be achieved in OAM multiplexed entanglement with LG modes based on the FWM process. In addition, we experimentally measure the entanglement with coherent superposition OAM modes. Our scheme provides a new, to the best of our knowledge, platform to construct an OAM multiplexed system and may find potential applications in realizing the parallel quantum information protocols.

Optics Letters•Feb 27, 2023•4 citations

Four-Wave Mixing with Orbital Angular Momentum Transfer

Hana Warner

We explore the conservation of orbital angular momentum (OAM) in the four-wave mixing (FWM) process in hot rubidium vapor. Since most modern communication systems send data in pulses corresponding to bits, we can use OAM to encode more information in each pulse by assigning structure to each signal. Furthermore, because FWM can be used to generate entangled photon pairs, we can use this process to bring enhanced signal security. We experimentally studied FWM with a wide range of Laguerre-Gaussian modes and their superpositions and observed OAM transfer from the probe field to a generated Stokes field. By studying the output Stokes intensity and phase distributions, we confirm l mode (OAM) conservation for pure l and p modes, as well as for the superpositions of l and -l for the mode numbers up to l = 4, p = 4. We also found that p index is generally not conserved and its conservation is highly dependent on the relative sizes of the probe and pump beams in the Rb cell. We also identify parameters to improve FWM gain with OAM transfer and propose an analytical method for determining OAM p number.

•Jan 1, 2020•0 citations

Deterministic distribution of orbital angular momentum multiplexed continuous-variable entanglement and quantum steering

Li Xia Zeng, Rong Ma, Hong Wen +4 more

Orbital angular momentum (OAM) multiplexing provides an efficient method to improve data-carrying capacity in various quantum communication protocols. It is a precondition to distribute OAM multiplexed quantum resources in quantum channels for implementing quantum communication. However, quantum steering of OAM multiplexed optical fields and the effect of channel noise on OAM multiplexed quantum resources remain unclear. Here, we generate OAM multiplexed continuous-variable (CV) entangled states and distribute them in lossy or noisy channels. We show that the decoherence property of entanglement and quantum steering of the OAM multiplexed states carrying topological charges l = 1 and l = 2 are the same as that of the Gaussian mode with l = 0 in lossy and noisy channels. The sudden death of entanglement and quantum steering of high-order OAM multiplexed states is observed in the presence of excess noise. Our results demonstrate the feasibility to realize high data-carrying capacity quantum information processing by utilizing OAM multiplexed CV entangled states.

arXiv:2203.15976•Photonics Research•Jan 28, 2022•19 citations
Multiplexing is crucial for the data-carrying capacity of information communication systems. Orbital angular momentum (OAM) with a topological charge \ensuremathℓ\ensuremath{\ell}\ensuremathℓ (\ensuremathℓ\ensuremath{\ell}\ensuremathℓ integer) provides a degree of freedom to realize multiplexing. In this Letter, we report an experimental implementation of OAM multiplexed continuous variables (CV) entanglement based on a four-wave mixing (FWM) process, in which 13 pairs of entangled Laguerre-Gauss (LG) modes, LG\ensuremathℓ,pr{\mathrm{LG}}_{\ensuremath{\ell},\mathrm{pr}}LG\ensuremathℓ,pr​ and LG\ensuremath−\ensuremathℓ,conj{\mathrm{LG}}_{\ensuremath{-}\ensuremath{\ell},\mathrm{conj}}LG\ensuremath−\ensuremathℓ,conj​, are simultaneously and deterministically generated, where \ensuremathℓ\ensuremath{\ell}\ensuremathℓ (\ensuremathℓ\ensuremath{\ell}\ensuremathℓ integer) is the topological charge corresponding to the OAM mode and pr (conj) indicates a probe (conjugate) beam. In the meanwhile, we experimentally show that there is no entanglement between the modes of LG\ensuremathℓ,pr{\mathrm{LG}}_{\ensuremath{\ell},\mathrm{pr}}LG\ensuremathℓ,pr​ and LG\ensuremathℓ,conj{\mathrm{LG}}_{\ensuremath{\ell},\mathrm{conj}}LG\ensuremathℓ,conj​ (\ensuremathℓ\ensuremath≠0\ensuremath{\ell}\ensuremath{\ne}0\ensuremathℓ\ensuremath=0). These results clearly confirm the conservation of OAM in the FWM process from the viewpoint of a CV system. In addition, we investigate the entanglement properties of three types of coherent superposition of OAM modes. In the end, we also study the effect of the pump beam radius on the number of OAM multiplexing. Such OAM multiplexed CV entanglement provides a new perspective and platform to study CV quantum information protocols.
We demonstrate the experimental generation of orbital angular momentum (OAM) multiplexed multipartite entanglement with cascaded four-wave mixing processes in a continuous variable (CV) system. In particular, we implement the simultaneous generation of 9 sets of OAM multiplexed tripartite entanglement over 27 Laguerre-Gauss (LG) modes, as well as 20 sets of OAM multiplexed bipartite entanglement over 40 LG modes, which show the rich entanglement structure of the system. In addition, we also generate tripartite entanglement of three types of coherent OAM superposition modes. Such OAM multiplexed multipartite entanglement opens the avenue to construct CV parallel quantum network for realizing parallel quantum information protocols.
Orbital angular momentum (OAM), characterized by a topological charge ℓ (ℓ integer), serves as a promising vehicle for carrying quantum information. Generating a nonclassical field involving two or more OAM modes can largely enhance the data-carrying capacity of quantum information processing. In this Letter, we present the implementation of a four-wave mixing (FWM) process, featuring a pump beam of a coherent OAM superposition mode and a probe beam of a single OAM mode. We generate twin beams encompassing multiple OAM modes and illustrate their quantum correlation when the pump beam assumes different coherent OAM superposition modes. Furthermore, we analyze the OAM mode components in each output field to deepen our understanding of the nonlinear interaction among different OAM modes. The obtained results show the rich structure of the nonlinear interaction of OAM modes in the FWM process and provide a perspective to study quantum information protocols.
In addition to carrying spin angular momentum (SAM), light can also possess orbital angular momentum (OAM), whose quantum number can, in principle, take any integer value. This property provides a new degree of freedom to expand the capacity of both classical and quantum information. In recent years, generating OAM multiplexed continuous-variable entanglement via four-wave mixing (FWM) has emerged as an effective approach to increasing the capacity of quantum information channels. Consequently, there is a growing demand for precise characterization of the OAM spectrum in such quantum beams. Here we present, to the best of our knowledge, the first experimental demonstration of OAM spectrum measurement in quantum optics using phase-shifting interferometry (PSI). This method enables accurate characterization of the OAM spectrum of both the probe and conjugate beams in OAM multiplexed continuous-variable entanglement generated via the FWM process. These results provide an experimental foundation for the reliable detection and utilization of multiplexed OAM degrees of freedom in quantum communication and quantum information processing.
We experimentally demonstrate a method for enhancing and flattening multiplexed entanglement in the four-wave mixing (FWM) process, which is implemented by replacing Laguerre-Gaussian (LG) modes with perfect vortex (PV) modes. For the topological charge l ranging from -5 to 5, the entanglement degrees of orbital angular momentum (OAM) multiplexed entanglement with PV modes are all larger than those of OAM multiplexed entanglement with LG modes. More importantly, for OAM multiplexed entanglement with PV modes, the degree of entanglement almost does not change with the topology value. In other words, we experimentally flatten the OAM multiplexed entanglement, which cannot be achieved in OAM multiplexed entanglement with LG modes based on the FWM process. In addition, we experimentally measure the entanglement with coherent superposition OAM modes. Our scheme provides a new, to the best of our knowledge, platform to construct an OAM multiplexed system and may find potential applications in realizing the parallel quantum information protocols.
We explore the conservation of orbital angular momentum (OAM) in the four-wave mixing (FWM) process in hot rubidium vapor. Since most modern communication systems send data in pulses corresponding to bits, we can use OAM to encode more information in each pulse by assigning structure to each signal. Furthermore, because FWM can be used to generate entangled photon pairs, we can use this process to bring enhanced signal security. We experimentally studied FWM with a wide range of Laguerre-Gaussian modes and their superpositions and observed OAM transfer from the probe field to a generated Stokes field. By studying the output Stokes intensity and phase distributions, we confirm l mode (OAM) conservation for pure l and p modes, as well as for the superpositions of l and -l for the mode numbers up to l = 4, p = 4. We also found that p index is generally not conserved and its conservation is highly dependent on the relative sizes of the probe and pump beams in the Rb cell. We also identify parameters to improve FWM gain with OAM transfer and propose an analytical method for determining OAM p number.
Orbital angular momentum (OAM) multiplexing provides an efficient method to improve data-carrying capacity in various quantum communication protocols. It is a precondition to distribute OAM multiplexed quantum resources in quantum channels for implementing quantum communication. However, quantum steering of OAM multiplexed optical fields and the effect of channel noise on OAM multiplexed quantum resources remain unclear. Here, we generate OAM multiplexed continuous-variable (CV) entangled states and distribute them in lossy or noisy channels. We show that the decoherence property of entanglement and quantum steering of the OAM multiplexed states carrying topological charges l = 1 and l = 2 are the same as that of the Gaussian mode with l = 0 in lossy and noisy channels. The sudden death of entanglement and quantum steering of high-order OAM multiplexed states is observed in the presence of excess noise. Our results demonstrate the feasibility to realize high data-carrying capacity quantum information processing by utilizing OAM multiplexed CV entangled states.