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

International Journal of Quantum Information

The Semi-Quantum Computer

Reinaldo O. Vianna, WILSON Ricardo Matos Rabelo, Carlos Henrique Monken

Published Jun 1, 2003• 1 citation
Publisher

Abstract

We discuss the performance of the Search and Fourier Transform algorithms on a hybrid computer constituted of classical and quantum processors working together. We show that this semi-quantum computer would be an improvement over a pure classical architecture, no matter how few qubits are available and, therefore, it suggests an easier implementable technology than a pure quantum computer with arbitrary number of qubits.

DOI
10.1142/s021974990300019x

Related papers

The Semi-Quantum Computer

Reinaldo O. Vianna, WILSON Ricardo Matos Rabelo, Carlos Henrique Monken

We discuss the performance of the Search and Fourier Transform algorithms on a hybrid computer constituted of classical and quantum processors working together. We show that this semi-quantum computer would be an improvement over a pure classical architecture, no matter how few qubits are available and, therefore, it suggests an easier implementable technology than a pure quantum computer with arbitrary number of qubits.

arXiv:quant-ph/0304085•Apr 11, 2003•0 citations

A Hybrid Quantum Search Engine: A Fast Quantum Algorithm for Multiple Matches

Ahmed Younes, Jon Rowe, Julian Francis Miller

In this paper we will present a quantum algorithm which works very efficiently in case of multiple matches within the search space and in the case of few matches, the algorithm performs classically. This allows us to propose a hybrid quantum search engine that integrates Grover's algorithm and the proposed algorithm here to have general performance better that any pure classical or quantum search algorithm.

arXiv:quant-ph/0311171•Nov 25, 2003•7 citations

Digital-analog quantum algorithm for the quantum Fourier transform

Ana Martin, Lamata Manuel, Lucas, E. Solano +1 more

Quantum computers will allow calculations beyond existing classical computers. However, current technology is still too noisy and imperfect to construct a universal digital quantum computer with quantum error correction. Inspired by the evolution of classical computation, an alternative paradigm merging the flexibility of digital quantum computation with the robustness of analog quantum simulation has emerged. This universal paradigm is known as digital-analog quantum computing. Here, we introduce an efficient digital-analog quantum algorithm to compute the quantum Fourier transform, a subroutine widely employed in several relevant quantum algorithms. We show that, under reasonable assumptions about noise models, the fidelity of the quantum Fourier transformation improves considerably using this approach when the number of qubits involved grows. This suggests that, in the noisy intermediate-scale quantum era, hybrid protocols combining digital and analog quantum computing could be a sensible approach to reach useful quantum supremacy.

•Jan 1, 2020•28 citations

Hybrid Quantum-classical Search Algorithms

Ansis Rosmanis

Search is one of the most commonly used primitives in quantum algorithm design. It is known that quadratic speedups provided by Grover’s algorithm are optimal, and no faster quantum algorithms for Search exist. While it is known that at least some quantum computation is required to achieve these speedups, the existing bounds do not rule out the possibility of an equally fast hybrid quantum-classical algorithm where most of the computation is classical. In this work, we study such hybrid algorithms, and we show that classical computation, unless it by itself can solve the Search problem, cannot assist quantum computation. In addition, we generalize this result to algorithms with subconstant success probabilities.

arXiv:2202.11443•ACM Transactions on Quantum Computing•Feb 16, 2024•12 citations

Algoritmos para a informação quântica: discriminação de estados quânticos e modelo híbrido

WILSON Ricardo Matos Rabelo

In this thesis we consider a protocol to perform the optimal quantum state discrimination of N linearly independent non-orthogonal pure quantum states. This protocol obtains the best set of generalized measurements for the problem of the unambiguous state discrimination. Through the extension of the Hilbert space, it is possible to perform an unitary operation yielding a final configuration, which gives the best discrimination. We introduce a detailed mathematical procedure to realize this task by means of semidefinite programming and norm minimization. The former is used to fix which is the best detection conclusive probability amplitude for each quantum state of the ensemble. The latter determines the matrix which leads the input states to the final configuration. In a final step, we decompose the unitary transformation in a sequence of 1-qubit rotation matrices. Subsequently, we show applications of the protocol in the quantum cryptography and state filtering, and present a computational code in MATLAB. Our additional result deals with the computational hybrid models. In particular, we study the Semi-quantum Computer. We discuss the performance of the Search and Fourier Transform algorithms on a hybrid architecture constituted of classical and quantum processors working together. We show that the semi-quantum computer can reach an improvement over a pure classical architecture, no matter how few qubits are available and, therefore, it suggests an easier implementable technology.

•Nov 24, 2006•1 citation

Hybrid Quantum-Classical Computers: A Critical Analysis to Quantum Computational Models

Azita Hajizade, Riccardo Bassoli, Frank H. P. Fitzek

Quantum computers can often be used in a hybrid setting, where classical computers still play an important role in the operation and use of the quantum computer. A hybrid architecture can serve as a foundational paradigm for realizing the early potential of quantum technologies, allowing us to combine the advantages of classical systems with the emerging capabilities of quantum processors to enable useful computations despite hardware limitations. Keeping the Turing machine for the classical part, this paper provides 5 types of quantum computational models and investigates the key effects and challenges of each from a theoretical point of view. In addition, it gives an overview of the key properties and recent advances to integrate the most efficient and feasible hybrid scheme based on the application in our Quantum Network.

IEEE Future Networks World Forum (FNWF)•Nov 10, 2025•0 citations
We discuss the performance of the Search and Fourier Transform algorithms on a hybrid computer constituted of classical and quantum processors working together. We show that this semi-quantum computer would be an improvement over a pure classical architecture, no matter how few qubits are available and, therefore, it suggests an easier implementable technology than a pure quantum computer with arbitrary number of qubits.
Quantum computers will allow calculations beyond existing classical computers. However, current technology is still too noisy and imperfect to construct a universal digital quantum computer with quantum error correction. Inspired by the evolution of classical computation, an alternative paradigm merging the flexibility of digital quantum computation with the robustness of analog quantum simulation has emerged. This universal paradigm is known as digital-analog quantum computing. Here, we introduce an efficient digital-analog quantum algorithm to compute the quantum Fourier transform, a subroutine widely employed in several relevant quantum algorithms. We show that, under reasonable assumptions about noise models, the fidelity of the quantum Fourier transformation improves considerably using this approach when the number of qubits involved grows. This suggests that, in the noisy intermediate-scale quantum era, hybrid protocols combining digital and analog quantum computing could be a sensible approach to reach useful quantum supremacy.
Search is one of the most commonly used primitives in quantum algorithm design. It is known that quadratic speedups provided by Grover’s algorithm are optimal, and no faster quantum algorithms for Search exist. While it is known that at least some quantum computation is required to achieve these speedups, the existing bounds do not rule out the possibility of an equally fast hybrid quantum-classical algorithm where most of the computation is classical. In this work, we study such hybrid algorithms, and we show that classical computation, unless it by itself can solve the Search problem, cannot assist quantum computation. In addition, we generalize this result to algorithms with subconstant success probabilities.
In this thesis we consider a protocol to perform the optimal quantum state discrimination of N linearly independent non-orthogonal pure quantum states. This protocol obtains the best set of generalized measurements for the problem of the unambiguous state discrimination. Through the extension of the Hilbert space, it is possible to perform an unitary operation yielding a final configuration, which gives the best discrimination. We introduce a detailed mathematical procedure to realize this task by means of semidefinite programming and norm minimization. The former is used to fix which is the best detection conclusive probability amplitude for each quantum state of the ensemble. The latter determines the matrix which leads the input states to the final configuration. In a final step, we decompose the unitary transformation in a sequence of 1-qubit rotation matrices. Subsequently, we show applications of the protocol in the quantum cryptography and state filtering, and present a computational code in MATLAB. Our additional result deals with the computational hybrid models. In particular, we study the Semi-quantum Computer. We discuss the performance of the Search and Fourier Transform algorithms on a hybrid architecture constituted of classical and quantum processors working together. We show that the semi-quantum computer can reach an improvement over a pure classical architecture, no matter how few qubits are available and, therefore, it suggests an easier implementable technology.
Quantum computers can often be used in a hybrid setting, where classical computers still play an important role in the operation and use of the quantum computer. A hybrid architecture can serve as a foundational paradigm for realizing the early potential of quantum technologies, allowing us to combine the advantages of classical systems with the emerging capabilities of quantum processors to enable useful computations despite hardware limitations. Keeping the Turing machine for the classical part, this paper provides 5 types of quantum computational models and investigates the key effects and challenges of each from a theoretical point of view. In addition, it gives an overview of the key properties and recent advances to integrate the most efficient and feasible hybrid scheme based on the application in our Quantum Network.