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

Photon Angular-Momentum-Entropy Conversion (PASEC): A Theoretical Framework for Information-Thermodynamic Bridge in Structured Light

Jincheng Zhang

Published Aug 11, 2026• 0 citations
Publisher

Abstract

The unification of information theory and thermodynamics represents one of the most profound intellectual achievements in modern physics, historically bridged by principles such as Landauer's erasure bound and Szilard's engine. Concurrently, the exploration of structured light has revealed that photons can carry well-defined orbital angular momentum (OAM), opening vast multidimensional state spaces for optical communication, quantum information processing, and optical manipulation. In this paper, we propose the Photon Angular-Momentum-Entropy Conversion (PASEC) framework, establishing a rigorous theoretical foundation that demonstrates a direct, reversible, and quantitative conversion between the mechanical orbital angular momentum of light and information entropy. By conceptualizing programmable optical phase transformations as thermodynamic state functions, we derive the fundamental governing equations for PASEC, showing that changes in the OAM spectrum map directly onto Shannon and von Neumann entropy variations under constraint conditions. This formulation bypasses the traditional necessity of thermal dissipation for entropy changes, offering an alternative purely mechanical-informational pathway. We explore the thermodynamic consistency of the framework, formulating a generalized optical Landauer principle where spatial mode compression and expansion act as thermodynamic compression and expansion cycles. Finally, we discuss the profound implications of establishing photon angular-momentum thermodynamics, outlining pathways toward macroscopic quantum entropy control using modern programmable spatial light modulators and metasurfaces.

DOI
10.5281/zenodo.21888375

Related papers

Emulating a quantum Maxwell’s demon with nonseparable structured light

Edgar Medina-Segura, Paola Concha Obando, Light Mkhumbuza +6 more

Maxwell’s demon (MD) has proven to be an instructive vehicle for exploring the relationship between information theory and thermodynamics. A long-standing debate has been the concern of entropy violation, now resolved by the introduction of a quantum MD that can enact reversible operations on a system. However, implementing it experimentally is challenging, as it demands precise control over multi-particle entangled states and the execution of entangling and disentangling operations with high accuracy. Here, we show how this can be emulated using vectorial structured light that is nonseparable in the spin and orbital angular momentum (OAM) internal degrees of freedom of each photon in a classical laser beam. We experimentally demonstrate that the demon’s classical entropy, linked to the uncertainty in spin degree of freedom of each photon, increases during the process while that in the system’s state (represented by OAM per photon) decreases. This is achieved by entangling the demon’s memory with the system, allowing the demon to acquire quantum information and utilize it to control the OAM states of the system after a disentangling operation. As a result, we demonstrate that the quantum demon can emulate the extraction of useful work from the system in the form of OAM, thereby opening a path to information-driven optical spanners for the mechanical rotation of objects using light. Our demonstration can easily be extrapolated to other degrees of freedom, for robust and scalable implementations of MDs at both the classical and quantum realms, enlightening the role of a structured light as a tool for exploiting principles in thermodynamics to control and measure information.

arXiv:2411.03893•Photonics Research•Aug 12, 2025•4 citations

Quantum Mechanical Properties of Light Fields Carrying Orbital Angular Momentum

Robert W. Boyd, Miles J. Padgett

This Chapter presents a review of the quantum mechanical properties of spatially structured light fields, specifically those fields carrying orbital angular momentum (OAM). This review is concerned both with the conceptual understanding of the quantum features of these light fields and with the use of these features for applications. We describe how to produce spatially entangled light fields by means of the nonlinear optical process of parametric downconversion. We ask and provide a tentative answer to the question of how much information can be encoded into a single photon. As an example, we review a recent experiment that demonstrated the ability to discriminate among four target objects using only one photon for illumination. We also present a description of the concept of the OAM of light, and we describe means to generate and detect OAM. We then present a brief survey of some recent studies of the fundamental quantum properties of structured light beams. Much of this work is aimed at studying the nature of entanglement for the complementary variables of angular position and OAM. Finally, as a realworld application, we describe a secure communication system based on quantum key distribution (QKD). This key distribution system makes use of encoding information in the OAM modes of light and hence is able to transmit more than one bit of information per photon. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Springer eBooks•Jan 1, 2016•3 citations

Angular momentum conversion in the influence of vortex light on electromagnetically induced transparency

Tang Jiangmin, ZHANG Jingtao

In the burgeoning field of light-matter interactions, angular momentum has emerged as a pivotal factor, driving innovative research directions. This study delves into the interaction dynamics between vortex lights and an electromagnetically induced transparency (EIT) medium, with a primary focus on elucidating the underlying mechanism of angular momentum transfer. Through comprehensive theoretical analysis and numerical simulations, it is demonstrated that when the probe field carries orbital angular momentum (OAM), the dispersion and absorption characteristics of the EIT medium undergo periodic modulation. This modulation is intricately determined by the azimuthal phase and topological charge of the beam. Notably, the OAM in the driving field exerts no such influence on the medium's properties. Leveraging vortex phase plates (VPPs) or spatial light modulators (SLMs) to manipulate the tunable OAM enables dynamic control over the EIT effect. This breakthrough not only deepens our understanding of light-matter interactions at the quantum level but also unlocks new avenues for high-dimensional quantum information processing and advanced optical communication technologies.

•Oct 1, 2025•0 citations

Generation and manipulation of laser beams carrying orbital angular momentum for classical and quantum information applications

Ebrahim Karimi

Light orbital angular momentum (OAM) has been recognized as a new promising resource for classical and quantum information applications. In contrast to the spin angular momentum, the OAM is an inherently multidimensional. Thus, the information can be encoded in the higher-dimensional OAM alphabets. Recently, Marrucci et al. have invented a new device named q-plate (QP), made of liquid crystal cell patterned in such a way to introduce a topological charge q at the transverse plane, which is able to generate a well-defined values of photon OAM. My research has been aimed at investigating the physics of the QP, of the optical fields that it generates and of its possible applications for optical communication and quantum information. We studied both theoretically and experimentally a novel set of non-orthogonal but over-complete paraxial modes, named Hypergeometric-Gaussian modes, that is typically associated with OAM-carrying optical fields. We have also found the light propagation kernel inside the QP and we have shown analytically that if small losses due to reflection, absorption, and scattering are neglected, the QP can convert the photon spin into OAM with up to 100 \% efficiency. We implemented a technique to control the QP optical retardation by tuning the QP temperature. At the optimal temperature, the QP can generate a beam with up to 97\% efficiency. Moreover, the OAM state generated by QP can be rotated easily in the 2D OAM Hilbert space by proper manipulation of the input polarization state, a fact which opens a new way of beam shape controlling in MHz scale. We also performed a novel way to encode and read two bits information on the 4D OAM space by using only one QP. Finally, we experimentally demonstrated the transfer of quantum information from spin to OAM and vice versa, including the case of bi-photon states having quantum correlations. Furthermore, by exploiting these quantum information transfer devices, we demonstrated the Hong-Ou-Mandel effect and the optimal quantum cloning with OAM-carrying photons.

•Jan 1, 2009•7 citations

Structured light with orbital angular momentum (OAM) for scalable quantum gate operations

Ayush Mehra, Shlomi Arnon

Structured light carrying Orbital Angular Momentum (OAM) enables high-dimensional photonic quantum information processing. In this work, we propose and theoretically demonstrate a four-dimensional controlledNOT (CNOT) quantum gate implemented using the radial (p) and azimuthal (l) degrees of freedom of Laguerre–Gaussian modes. Quantum information is encoded within a single photon, with the radial mode acting as the control qubit and the OAM mode as the target qubit. The gate is realized using fully linear and unitary optical transformations based on Fourier transform based radial mode sorting and OAM inversion within the architecture. This approach enables deterministic two-qubit logic in an expanded Hilbert space, providing a scalable pathway toward high-dimensional quantum gates using structured light.

Quantum Computing, Communication, and Simulation•Mar 5, 2026•1 citation

Orbital angular momentum of light towards implementation of high-dimensional quantum gates

Juan Carlos Rojas Velásquez

High-dimensional quantum computing has emerged as a recent alternative to conventional qubit-based approaches, offering advantages such as an increased information density and enhanced robustness against noise. In this work, we explore the use of the orbital angular momentum (OAM) of light as a degree of freedom in which high-dimensional quantum gates can be implemented. We present a theoretical and experimental study of structured light beams carrying OAM, with emphasis on Laguerre–Gauss modes, as a natural basis for high-dimensional quantum computing. We then describe the generation of OAM beams using computer-generated holograms and spatial light modulators, detailing practical methods for encoding arbitrary phase profiles. Building on this framework, we analyze the implementation of high-dimensional quantum logic gates, focusing on the generalized Pauli Z_d and X_d operations. Optical setups based on Dove prisms, Sagnac interferometers, spiral phase plates, and parity sorters are proposed and theoretically validated. Finally, we report experimental results demonstrating the generation of Laguerre–Gauss beams, the transformation properties of Dove prisms, and the operation of a parity sorter, which constitutes a building block for realizing high-dimensional quantum gates. These results establish a solid foundation for future implementations of high-dimensional quantum information processing using the orbital angular momentum of light.

•Jan 21, 2026•0 citations
The unification of information theory and thermodynamics represents one of the most profound intellectual achievements in modern physics, historically bridged by principles such as Landauer's erasure bound and Szilard's engine. Concurrently, the exploration of structured light has revealed that photons can carry well-defined orbital angular momentum (OAM), opening vast multidimensional state spaces for optical communication, quantum information processing, and optical manipulation. In this paper, we propose the Photon Angular-Momentum-Entropy Conversion (PASEC) framework, establishing a rigorous theoretical foundation that demonstrates a direct, reversible, and quantitative conversion between the mechanical orbital angular momentum of light and information entropy. By conceptualizing programmable optical phase transformations as thermodynamic state functions, we derive the fundamental governing equations for PASEC, showing that changes in the OAM spectrum map directly onto Shannon and von Neumann entropy variations under constraint conditions. This formulation bypasses the traditional necessity of thermal dissipation for entropy changes, offering an alternative purely mechanical-informational pathway. We explore the thermodynamic consistency of the framework, formulating a generalized optical Landauer principle where spatial mode compression and expansion act as thermodynamic compression and expansion cycles. Finally, we discuss the profound implications of establishing photon angular-momentum thermodynamics, outlining pathways toward macroscopic quantum entropy control using modern programmable spatial light modulators and metasurfaces.
Maxwell’s demon (MD) has proven to be an instructive vehicle for exploring the relationship between information theory and thermodynamics. A long-standing debate has been the concern of entropy violation, now resolved by the introduction of a quantum MD that can enact reversible operations on a system. However, implementing it experimentally is challenging, as it demands precise control over multi-particle entangled states and the execution of entangling and disentangling operations with high accuracy. Here, we show how this can be emulated using vectorial structured light that is nonseparable in the spin and orbital angular momentum (OAM) internal degrees of freedom of each photon in a classical laser beam. We experimentally demonstrate that the demon’s classical entropy, linked to the uncertainty in spin degree of freedom of each photon, increases during the process while that in the system’s state (represented by OAM per photon) decreases. This is achieved by entangling the demon’s memory with the system, allowing the demon to acquire quantum information and utilize it to control the OAM states of the system after a disentangling operation. As a result, we demonstrate that the quantum demon can emulate the extraction of useful work from the system in the form of OAM, thereby opening a path to information-driven optical spanners for the mechanical rotation of objects using light. Our demonstration can easily be extrapolated to other degrees of freedom, for robust and scalable implementations of MDs at both the classical and quantum realms, enlightening the role of a structured light as a tool for exploiting principles in thermodynamics to control and measure information.
This Chapter presents a review of the quantum mechanical properties of spatially structured light fields, specifically those fields carrying orbital angular momentum (OAM). This review is concerned both with the conceptual understanding of the quantum features of these light fields and with the use of these features for applications. We describe how to produce spatially entangled light fields by means of the nonlinear optical process of parametric downconversion. We ask and provide a tentative answer to the question of how much information can be encoded into a single photon. As an example, we review a recent experiment that demonstrated the ability to discriminate among four target objects using only one photon for illumination. We also present a description of the concept of the OAM of light, and we describe means to generate and detect OAM. We then present a brief survey of some recent studies of the fundamental quantum properties of structured light beams. Much of this work is aimed at studying the nature of entanglement for the complementary variables of angular position and OAM. Finally, as a realworld application, we describe a secure communication system based on quantum key distribution (QKD). This key distribution system makes use of encoding information in the OAM modes of light and hence is able to transmit more than one bit of information per photon. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
In the burgeoning field of light-matter interactions, angular momentum has emerged as a pivotal factor, driving innovative research directions. This study delves into the interaction dynamics between vortex lights and an electromagnetically induced transparency (EIT) medium, with a primary focus on elucidating the underlying mechanism of angular momentum transfer. Through comprehensive theoretical analysis and numerical simulations, it is demonstrated that when the probe field carries orbital angular momentum (OAM), the dispersion and absorption characteristics of the EIT medium undergo periodic modulation. This modulation is intricately determined by the azimuthal phase and topological charge of the beam. Notably, the OAM in the driving field exerts no such influence on the medium's properties. Leveraging vortex phase plates (VPPs) or spatial light modulators (SLMs) to manipulate the tunable OAM enables dynamic control over the EIT effect. This breakthrough not only deepens our understanding of light-matter interactions at the quantum level but also unlocks new avenues for high-dimensional quantum information processing and advanced optical communication technologies.
Light orbital angular momentum (OAM) has been recognized as a new promising resource for classical and quantum information applications. In contrast to the spin angular momentum, the OAM is an inherently multidimensional. Thus, the information can be encoded in the higher-dimensional OAM alphabets. Recently, Marrucci et al. have invented a new device named q-plate (QP), made of liquid crystal cell patterned in such a way to introduce a topological charge q at the transverse plane, which is able to generate a well-defined values of photon OAM. My research has been aimed at investigating the physics of the QP, of the optical fields that it generates and of its possible applications for optical communication and quantum information. We studied both theoretically and experimentally a novel set of non-orthogonal but over-complete paraxial modes, named Hypergeometric-Gaussian modes, that is typically associated with OAM-carrying optical fields. We have also found the light propagation kernel inside the QP and we have shown analytically that if small losses due to reflection, absorption, and scattering are neglected, the QP can convert the photon spin into OAM with up to 100 \% efficiency. We implemented a technique to control the QP optical retardation by tuning the QP temperature. At the optimal temperature, the QP can generate a beam with up to 97\% efficiency. Moreover, the OAM state generated by QP can be rotated easily in the 2D OAM Hilbert space by proper manipulation of the input polarization state, a fact which opens a new way of beam shape controlling in MHz scale. We also performed a novel way to encode and read two bits information on the 4D OAM space by using only one QP. Finally, we experimentally demonstrated the transfer of quantum information from spin to OAM and vice versa, including the case of bi-photon states having quantum correlations. Furthermore, by exploiting these quantum information transfer devices, we demonstrated the Hong-Ou-Mandel effect and the optimal quantum cloning with OAM-carrying photons.
Structured light carrying Orbital Angular Momentum (OAM) enables high-dimensional photonic quantum information processing. In this work, we propose and theoretically demonstrate a four-dimensional controlledNOT (CNOT) quantum gate implemented using the radial (p) and azimuthal (l) degrees of freedom of Laguerre–Gaussian modes. Quantum information is encoded within a single photon, with the radial mode acting as the control qubit and the OAM mode as the target qubit. The gate is realized using fully linear and unitary optical transformations based on Fourier transform based radial mode sorting and OAM inversion within the architecture. This approach enables deterministic two-qubit logic in an expanded Hilbert space, providing a scalable pathway toward high-dimensional quantum gates using structured light.
High-dimensional quantum computing has emerged as a recent alternative to conventional qubit-based approaches, offering advantages such as an increased information density and enhanced robustness against noise. In this work, we explore the use of the orbital angular momentum (OAM) of light as a degree of freedom in which high-dimensional quantum gates can be implemented. We present a theoretical and experimental study of structured light beams carrying OAM, with emphasis on Laguerre–Gauss modes, as a natural basis for high-dimensional quantum computing. We then describe the generation of OAM beams using computer-generated holograms and spatial light modulators, detailing practical methods for encoding arbitrary phase profiles. Building on this framework, we analyze the implementation of high-dimensional quantum logic gates, focusing on the generalized Pauli Z_d and X_d operations. Optical setups based on Dove prisms, Sagnac interferometers, spiral phase plates, and parity sorters are proposed and theoretically validated. Finally, we report experimental results demonstrating the generation of Laguerre–Gauss beams, the transformation properties of Dove prisms, and the operation of a parity sorter, which constitutes a building block for realizing high-dimensional quantum gates. These results establish a solid foundation for future implementations of high-dimensional quantum information processing using the orbital angular momentum of light.