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

A quantum-bit encoding converter for quantum interconnects

Beate E. Asenbeck, Tom Darras, Giovanni Guccione, Adrien Cavaillès, Hanna Le Jeannic, Julien Laurat

Published Jan 1, 2023• 0 citations
Publisher

Abstract

Here we demonstrate the conversion of quantum information between optical discrete- and continuous-variable qubits. We certify the protocol with fidelities exceeding the classical limit. Our result demonstrates an essential tool for enabling interconnected quantum architectures.
DOI
10.1364/cleo_fs.2023.fth4a.2

Related papers

A quantum-bit encoding converter

Tom Darras, Beate E. Asenbeck, Giovanni Guccione +3 more

From telecommunication to computing architectures, the realm of classical information hinges on converter technology to enable the exchange of data between digital and analog formats, a process now routinely performed across a variety of electronic devices. A similar exigency exists as well in quantum information technology where different frameworks are being developed for quantum computing, communication, and sensing. Thus, efficient quantum interconnects are a major need to bring these parallel approaches together and scale up quantum information systems. So far, however, the conversion between different optical quantum-bit encodings has remained challenging due to the difficulty of preserving fragile quantum superpositions and the demanding requirements for postselection-free implementations. Here we demonstrate such a conversion of quantum information between the two main paradigms, namely discrete- and continuous-variable qubits. We certify the protocol on a complete set of single-photon qubits, successfully converting them to cat-state qubits with fidelities exceeding the classical limit. Our result demonstrates an essential tool for enabling interconnected quantum devices and architectures with enhanced versatility and scalability.

arXiv:2211.10457•Nov 18, 2022•0 citations

Optical quantum interconnects for networking

Julien Laurat

To advance quantum information science and technologies, a wide variety of quantum machines and protocols are being developed based on different physical systems. Interconnecting these systems is a grand challenge to scale up quantum information architectures. This effort requires to develop specialized photonic devices and capabilities, ranging from efficient photon extraction for qubit connectivity to the implementation of advanced optical memories. In this talk, I will provide an overview of the opportunities presented by networking, including long-distance quantum communications and distributed quantum computing. I will also present our recent experimental demonstrations, which enable the realization of a quantum-bit-encoding converter, the implementation and use of highly-efficient quantum memories based on laser-cooled neutral atoms, and the development of nanophotonic devices for qubit coupling.

Quantum Computing, Communication, and Simulation•Mar 5, 2026•0 citations

Optical quantum interconnects for networking

Julien Laurat

To advance quantum information science and technologies, a wide variety of quantum machines and protocols are being developed based on different physical systems. Interconnecting these systems is a grand challenge to scale up quantum information architectures. This effort requires to develop specialized photonic devices and capabilities, ranging from efficient photon extraction for qubit connectivity to the implementation of advanced optical memories. In this talk, I will provide an overview of the opportunities presented by networking, including long-distance quantum communication and distributed quantum computing. I will also present our recent experimental demonstrations, which enable the realization of a quantum-bit-encoding converter, the implementation and use of highly-efficient quantum memories based on laser-cooled neutral atoms, and the development of nanophotonic devices for qubit coupling.

Photonics for Quantum (PfQ)•Jul 18, 2025•0 citations

Quantum Teleportation Between Discrete and Continuous Encodings of an Optical Qubit

Alexander E. Ulanov, Demid Sychev, Anastasia A. Pushkina +2 more

The transfer of quantum information between physical systems of a different nature is a central matter in quantum technologies. Particularly challenging is the transfer between discrete and continuous degrees of freedom of various harmonic oscillator systems. Here we implement a protocol for teleporting a continuous-variable optical qubit, encoded by means of low-amplitude coherent states, onto a discrete-variable, single-rail qubit-a superposition of the vacuum and single-photon optical states-via a hybrid entangled resource. We test our protocol on a one-dimensional manifold of the input qubit space and demonstrate the mapping onto the equator of the teleported qubit's Bloch sphere with an average fidelity of 0.83±0.04. Our work opens up the way to the wide application of quantum information processing techniques where discrete- and continuous-variable encodings are combined within the same optical circuit.

arXiv:1605.08649•Physical Review Letters•Apr 17, 2017•97 citations

Quantum interface between single- and dual-rail optical qubits

David Drahi, Demid Sychev, Khurram K. Pirov +4 more

Today's most widely used method of encoding quantum information in optical qubits is the dual-rail basis, often carried out through the polarisation of a single photon. On the other hand, many stationary carriers of quantum information - such as atoms - couple to light via the single-rail encoding in which the qubit is encoded in the number of photons. As such, interconversion between the two encodings is paramount in order to achieve cohesive quantum networks. In this paper, we demonstrate this by generating an entangled resource between the two encodings and using it to teleport a dual-rail qubit onto its single-rail counterpart. Our results yield an average fidelity of $\mathcal{F}= (92.8\pm2.2)\%$ for the teleportation and $\mathcal{F}= (89.7\pm2.1)\%$ for entanglement swapping, thus confirming the applicability of this scheme for a real-world implementation. This work completes the set of tools necessary for the interconversion between the three primary encodings of the qubit in the optical field: single-rail, dual-rail and continuous-variable.

•May 21, 2019•3 citations

Qubit-Programmable Operations on Quantum Light Fields

Marco Barbieri, Nicolò Spagnolo, Franck Ferreyrol +3 more

Engineering quantum operations is a crucial capability needed for developing quantum technologies and designing new fundamental physics tests. Here we propose a scheme for realising a controlled operation acting on a travelling continuous-variable quantum field, whose functioning is determined by a discrete input qubit. This opens a new avenue for exploiting advantages of both information encoding approaches. Furthermore, this approach allows for the program itself to be in a superposition of operations, and as a result it can be used within a quantum processor, where coherences must be maintained. Our study can find interest not only in general quantum state engineering and information protocols, but also details an interface between different physical platforms. Potential applications can be found in linking optical qubits to optical systems for which coupling is best described in terms of their continuous variables, such as optomechanical devices.

arXiv:1412.0723•Scientific Reports•Oct 15, 2015•2 citations
From telecommunication to computing architectures, the realm of classical information hinges on converter technology to enable the exchange of data between digital and analog formats, a process now routinely performed across a variety of electronic devices. A similar exigency exists as well in quantum information technology where different frameworks are being developed for quantum computing, communication, and sensing. Thus, efficient quantum interconnects are a major need to bring these parallel approaches together and scale up quantum information systems. So far, however, the conversion between different optical quantum-bit encodings has remained challenging due to the difficulty of preserving fragile quantum superpositions and the demanding requirements for postselection-free implementations. Here we demonstrate such a conversion of quantum information between the two main paradigms, namely discrete- and continuous-variable qubits. We certify the protocol on a complete set of single-photon qubits, successfully converting them to cat-state qubits with fidelities exceeding the classical limit. Our result demonstrates an essential tool for enabling interconnected quantum devices and architectures with enhanced versatility and scalability.
To advance quantum information science and technologies, a wide variety of quantum machines and protocols are being developed based on different physical systems. Interconnecting these systems is a grand challenge to scale up quantum information architectures. This effort requires to develop specialized photonic devices and capabilities, ranging from efficient photon extraction for qubit connectivity to the implementation of advanced optical memories. In this talk, I will provide an overview of the opportunities presented by networking, including long-distance quantum communications and distributed quantum computing. I will also present our recent experimental demonstrations, which enable the realization of a quantum-bit-encoding converter, the implementation and use of highly-efficient quantum memories based on laser-cooled neutral atoms, and the development of nanophotonic devices for qubit coupling.
To advance quantum information science and technologies, a wide variety of quantum machines and protocols are being developed based on different physical systems. Interconnecting these systems is a grand challenge to scale up quantum information architectures. This effort requires to develop specialized photonic devices and capabilities, ranging from efficient photon extraction for qubit connectivity to the implementation of advanced optical memories. In this talk, I will provide an overview of the opportunities presented by networking, including long-distance quantum communication and distributed quantum computing. I will also present our recent experimental demonstrations, which enable the realization of a quantum-bit-encoding converter, the implementation and use of highly-efficient quantum memories based on laser-cooled neutral atoms, and the development of nanophotonic devices for qubit coupling.
The transfer of quantum information between physical systems of a different nature is a central matter in quantum technologies. Particularly challenging is the transfer between discrete and continuous degrees of freedom of various harmonic oscillator systems. Here we implement a protocol for teleporting a continuous-variable optical qubit, encoded by means of low-amplitude coherent states, onto a discrete-variable, single-rail qubit-a superposition of the vacuum and single-photon optical states-via a hybrid entangled resource. We test our protocol on a one-dimensional manifold of the input qubit space and demonstrate the mapping onto the equator of the teleported qubit's Bloch sphere with an average fidelity of 0.83±0.04. Our work opens up the way to the wide application of quantum information processing techniques where discrete- and continuous-variable encodings are combined within the same optical circuit.
Today's most widely used method of encoding quantum information in optical qubits is the dual-rail basis, often carried out through the polarisation of a single photon. On the other hand, many stationary carriers of quantum information - such as atoms - couple to light via the single-rail encoding in which the qubit is encoded in the number of photons. As such, interconversion between the two encodings is paramount in order to achieve cohesive quantum networks. In this paper, we demonstrate this by generating an entangled resource between the two encodings and using it to teleport a dual-rail qubit onto its single-rail counterpart. Our results yield an average fidelity of F=(92.8±2.2)%\mathcal{F}= (92.8\pm2.2)\%F=(92.8±2.2)% for the teleportation and F=(89.7±2.1)%\mathcal{F}= (89.7\pm2.1)\%F=(89.7±2.1)% for entanglement swapping, thus confirming the applicability of this scheme for a real-world implementation. This work completes the set of tools necessary for the interconversion between the three primary encodings of the qubit in the optical field: single-rail, dual-rail and continuous-variable.
Engineering quantum operations is a crucial capability needed for developing quantum technologies and designing new fundamental physics tests. Here we propose a scheme for realising a controlled operation acting on a travelling continuous-variable quantum field, whose functioning is determined by a discrete input qubit. This opens a new avenue for exploiting advantages of both information encoding approaches. Furthermore, this approach allows for the program itself to be in a superposition of operations, and as a result it can be used within a quantum processor, where coherences must be maintained. Our study can find interest not only in general quantum state engineering and information protocols, but also details an interface between different physical platforms. Potential applications can be found in linking optical qubits to optical systems for which coupling is best described in terms of their continuous variables, such as optomechanical devices.