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

IEEE Photonics Technology Letters

Photonic Implementation of Quantum Relay and Encoders/Decoders for Sparse-Graph Quantum Codes Based on Optical Hybrid

Ivan B. Djordjević

Published Jul 26, 2010• 20 citations
Publisher

Abstract

We show that any family of deterministic universal quantum gates can be implemented in integrated optics. We further show how to implement Pauli gates, needed in quantum-error correction, using the same technology. Two basic circuits required in quantum teleportation systems are Bell states and quantum relay. We describe how to implement them in integrated optics. Finally, we study the implementation of sparse-graph (SG) quantum codes in integrated optics. We demonstrate that entanglement assisted SG codes significantly outperform corresponding dual-containing quantum codes.

DOI
10.1109/lpt.2010.2060477

Related papers

On the Photonic Implementation of Universal Quantum Gates, Bell States Preparation Circuit, Quantum Relay and Quantum LDPC Encoders and Decoders

Ivan B. Djordjević

We show that any family of universal quantum gates can be implemented based on a single optical hybrid/Mach-Zehnder interferometer (MZI)/directional coupler (DC) and either a highly nonlinear optical fiber or a tap coupler with an avalanche photodiode. We further show how to implement Pauli gates, which are needed in quantum error correction, using the same technology. The use of Bell states in quantum teleportation is essential. We also show how to implement the Bell states preparation circuit. To extend the transmission distance of quantum teleportation systems, the use of quantum relays is necessary. We show how to implement the quantum relay in integrated optics as well. We further study the implementation of encoders/decoders for sparse-graph quantum codes and show that the encoder/decoder for arbitrary quantum sparse-graph code can be implemented in integrated optics as well. We also study the performance of sparse-graph codes and demonstrate that entanglement-assisted sparse-graph codes from balanced incomplete block designs significantly outperform the corresponding dual-containing quantum codes. Finally, we provide several theorems that can be used in the design of entanglement-assisted (EA) quantum codes that require only one qubit to be shared between the source and the destination.

IEEE photonics journal•Feb 1, 2010•15 citations

On the photonic implementation of universal quantum gates, Bell states preparation circuit and quantum LDPC encoders and decoders based on directional couplers and HNLF

Ivan B. Djordjević

The Bell states preparation circuit is a basic circuit required in quantum teleportation. We describe how to implement it in all-fiber technology. The basic building blocks for its implementation are directional couplers and highly nonlinear optical fiber (HNLF). Because the quantum information processing is based on delicate superposition states, it is sensitive to quantum errors. In order to enable fault-tolerant quantum computing the use of quantum error correction is unavoidable. We show how to implement in all-fiber technology encoders and decoders for sparse-graph quantum codes, and provide an illustrative example to demonstrate this implementation. We also show that arbitrary set of universal quantum gates can be implemented based on directional couplers and HNLFs.

Optics Express•Apr 1, 2010•5 citations

Photonic entanglement-assisted quantum low-density parity-check encoders and decoders

Ivan B. Djordjević

I propose encoder and decoder architectures for entanglement-assisted (EA) quantum low-density parity-check (LDPC) codes suitable for all-optical implementation. I show that two basic gates needed for EA quantum error correction, namely, controlled-NOT (CNOT) and Hadamard gates can be implemented based on Mach-Zehnder interferometer. In addition, I show that EA quantum LDPC codes from balanced incomplete block designs of unitary index require only one entanglement qubit to be shared between source and destination.

Optics Letters•Apr 28, 2010•34 citations

Photonic Quantum Dual-Containing LDPC Encoders and Decoders

Ivan B. Djordjević

We propose encoder and decoder architectures for quantum low-density parity-check (LDPC) codes suitable for all-optical implementation, based on controlled-not (CNOT) and Hadamard gates only. Given the fact that the CNOT gate can be implemented using directional couplers, and Hadamard gate by using pi-hybrid, the proposed encoders/decoders architectures are suitable for implementation in integrated optics. In addition, we propose several quantum LDPC codes based on balanced incomplete block designs.

IEEE Photonics Technology Letters•Apr 3, 2009•27 citations

Cavity Quantum Electrodynamics (CQED)-Based Quantum LDPC Encoders and Decoders

Ivan B. Djordjević

Quantum information processing (QIP) relies on delicate superposition states that are sensitive to interactions with environment, resulting in errors. Moreover, the quantum gates are imperfect so that the use of quantum error correction coding (QECC) is essential to enable the fault-tolerant computing. The QECC is also important in quantum communication and teleportation applications. The most critical gate, i.e., the CNOT gate, has been implemented recently as a probabilistic device by using integrated optics. CNOT gates from linear optics provide only probabilistic outcomes and, as such, are not suitable for any meaningful quantum computation (on the order of thousand qubits and above). In this paper, we show that arbitrary set of universal quantum gates and gates from Clifford group, which are needed in QECC, can be implemented based on cavity quantum electrodynamics (CQED). Moreover, in CQED technology, the use of the controlled-Zgate instead of the CNOT gate is more appropriate. We then show that encoders/decoders for quantum low-density parity-check (LDPC) codes can be implemented based on Hadamard and controlled-Zgates only using CQED. We also discuss quantum dual-containing and entanglement-assisted codes and show that they can be related to combinatorial objects known as balanced incomplete block designs (BIBDs). In particular, a special class of BIBDs-Steiner triple systems (STSs)-yields to low-complexity quantum LDPC codes. Finally, we perform simulations and evaluate the performance of several classes of large-girth quantum LDPC codes suitable for implementation in CQED technology against that of lower girth entanglement-assisted codes and dual-containing quantum codes.

IEEE photonics journal•Jul 21, 2011•9 citations

Quantum circuit mapping for universal and scalable computing in MZI-based integrated photonics

Yong Sung Kwon, Alessio Baldazzi, Lorenzo Pavesi +1 more

Linear optical quantum computing (LOQC) offers a quantum computation paradigm based on well-established and robust technology and flexible environmental conditions following DiVincenzo's criteria. Within this framework, integrated photonics can be utilized to achieve gate-based quantum computing, defining qubits by path-encoding, quantum gates through the use of Mach-Zehnder interferometers (MZIs), and measurements through single-photon detectors. In particular, universal two-qubit gates can be achieved by suitable structures of MZIs together with post-selection or heralding. The most resource-efficient choice is given by the post-selected Controlled-Z (CZ) gate. However, this implementation is characterized by a design which has a non-regular structure and cannot be cascaded. This limits the implementation of large-scale LOQC. Starting from these issues, we suggest an approach to move toward a universal and scalable LOQC on the integrated photonic platform. First of all, choosing the post-selected CZ as a universal two-qubit gate, we extend the path-encoded dual-rail qubit to a triplet of waveguides, composed of an auxiliary waveguide and the pair of waveguides corresponding to the qubit basis states. Additionally, we introduce a swap photonic network that maps the regularly-labeled structure of the new path-encoded qubits to the structure needed for the post-selected CZ. We also discuss the optical swap gate that allows the connection of non-nearest neighbor path-encoded qubits. In this way, we can deterministically exchange the locations of the qubits and execute controlled quantum gates between any path-encoded qubits. Next, by truncating the auxiliary waveguides after any post-selected CZ, we find that it is possible to cascade this optical gate when it acts on different pairs that share only one qubit. Finally, we show the Bell state and the Greenberger-Horne-Zeilinger (GHZ) state generation circuits implementing the regular structure, the cascading procedure of post-selected CZ and the optical swap.

arXiv:2401.16875•Optics Express•Mar 13, 2024•12 citations
We show that any family of deterministic universal quantum gates can be implemented in integrated optics. We further show how to implement Pauli gates, needed in quantum-error correction, using the same technology. Two basic circuits required in quantum teleportation systems are Bell states and quantum relay. We describe how to implement them in integrated optics. Finally, we study the implementation of sparse-graph (SG) quantum codes in integrated optics. We demonstrate that entanglement assisted SG codes significantly outperform corresponding dual-containing quantum codes.
We show that any family of universal quantum gates can be implemented based on a single optical hybrid/Mach-Zehnder interferometer (MZI)/directional coupler (DC) and either a highly nonlinear optical fiber or a tap coupler with an avalanche photodiode. We further show how to implement Pauli gates, which are needed in quantum error correction, using the same technology. The use of Bell states in quantum teleportation is essential. We also show how to implement the Bell states preparation circuit. To extend the transmission distance of quantum teleportation systems, the use of quantum relays is necessary. We show how to implement the quantum relay in integrated optics as well. We further study the implementation of encoders/decoders for sparse-graph quantum codes and show that the encoder/decoder for arbitrary quantum sparse-graph code can be implemented in integrated optics as well. We also study the performance of sparse-graph codes and demonstrate that entanglement-assisted sparse-graph codes from balanced incomplete block designs significantly outperform the corresponding dual-containing quantum codes. Finally, we provide several theorems that can be used in the design of entanglement-assisted (EA) quantum codes that require only one qubit to be shared between the source and the destination.
The Bell states preparation circuit is a basic circuit required in quantum teleportation. We describe how to implement it in all-fiber technology. The basic building blocks for its implementation are directional couplers and highly nonlinear optical fiber (HNLF). Because the quantum information processing is based on delicate superposition states, it is sensitive to quantum errors. In order to enable fault-tolerant quantum computing the use of quantum error correction is unavoidable. We show how to implement in all-fiber technology encoders and decoders for sparse-graph quantum codes, and provide an illustrative example to demonstrate this implementation. We also show that arbitrary set of universal quantum gates can be implemented based on directional couplers and HNLFs.
I propose encoder and decoder architectures for entanglement-assisted (EA) quantum low-density parity-check (LDPC) codes suitable for all-optical implementation. I show that two basic gates needed for EA quantum error correction, namely, controlled-NOT (CNOT) and Hadamard gates can be implemented based on Mach-Zehnder interferometer. In addition, I show that EA quantum LDPC codes from balanced incomplete block designs of unitary index require only one entanglement qubit to be shared between source and destination.
We propose encoder and decoder architectures for quantum low-density parity-check (LDPC) codes suitable for all-optical implementation, based on controlled-not (CNOT) and Hadamard gates only. Given the fact that the CNOT gate can be implemented using directional couplers, and Hadamard gate by using pi-hybrid, the proposed encoders/decoders architectures are suitable for implementation in integrated optics. In addition, we propose several quantum LDPC codes based on balanced incomplete block designs.
Quantum information processing (QIP) relies on delicate superposition states that are sensitive to interactions with environment, resulting in errors. Moreover, the quantum gates are imperfect so that the use of quantum error correction coding (QECC) is essential to enable the fault-tolerant computing. The QECC is also important in quantum communication and teleportation applications. The most critical gate, i.e., the CNOT gate, has been implemented recently as a probabilistic device by using integrated optics. CNOT gates from linear optics provide only probabilistic outcomes and, as such, are not suitable for any meaningful quantum computation (on the order of thousand qubits and above). In this paper, we show that arbitrary set of universal quantum gates and gates from Clifford group, which are needed in QECC, can be implemented based on cavity quantum electrodynamics (CQED). Moreover, in CQED technology, the use of the controlled-Zgate instead of the CNOT gate is more appropriate. We then show that encoders/decoders for quantum low-density parity-check (LDPC) codes can be implemented based on Hadamard and controlled-Zgates only using CQED. We also discuss quantum dual-containing and entanglement-assisted codes and show that they can be related to combinatorial objects known as balanced incomplete block designs (BIBDs). In particular, a special class of BIBDs-Steiner triple systems (STSs)-yields to low-complexity quantum LDPC codes. Finally, we perform simulations and evaluate the performance of several classes of large-girth quantum LDPC codes suitable for implementation in CQED technology against that of lower girth entanglement-assisted codes and dual-containing quantum codes.
Linear optical quantum computing (LOQC) offers a quantum computation paradigm based on well-established and robust technology and flexible environmental conditions following DiVincenzo's criteria. Within this framework, integrated photonics can be utilized to achieve gate-based quantum computing, defining qubits by path-encoding, quantum gates through the use of Mach-Zehnder interferometers (MZIs), and measurements through single-photon detectors. In particular, universal two-qubit gates can be achieved by suitable structures of MZIs together with post-selection or heralding. The most resource-efficient choice is given by the post-selected Controlled-Z (CZ) gate. However, this implementation is characterized by a design which has a non-regular structure and cannot be cascaded. This limits the implementation of large-scale LOQC. Starting from these issues, we suggest an approach to move toward a universal and scalable LOQC on the integrated photonic platform. First of all, choosing the post-selected CZ as a universal two-qubit gate, we extend the path-encoded dual-rail qubit to a triplet of waveguides, composed of an auxiliary waveguide and the pair of waveguides corresponding to the qubit basis states. Additionally, we introduce a swap photonic network that maps the regularly-labeled structure of the new path-encoded qubits to the structure needed for the post-selected CZ. We also discuss the optical swap gate that allows the connection of non-nearest neighbor path-encoded qubits. In this way, we can deterministically exchange the locations of the qubits and execute controlled quantum gates between any path-encoded qubits. Next, by truncating the auxiliary waveguides after any post-selected CZ, we find that it is possible to cascade this optical gate when it acts on different pairs that share only one qubit. Finally, we show the Bell state and the Greenberger-Horne-Zeilinger (GHZ) state generation circuits implementing the regular structure, the cascading procedure of post-selected CZ and the optical swap.