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16 Results Found

  • Review
  • Open Access
983 Views
30 Pages

27 June 2026

Variational quantum algorithms (VQAs) are a leading framework for realizing quantum advantages in the Noisy Intermediate-Scale Quantum (NISQ) era, with applications spanning discrete combinatorial problems and continuous optimization. While the topol...

(This article belongs to the Special Issue Control, Optimization and Scheduling of Smart Distribution Grids)
  • Proceeding Paper
  • Open Access
959 Views
14 Pages

The quantum approximate optimization algorithm (QAOA) is an efficient method for solving combinatorial optimization problems in quantum computing. These problems involve finding the best solution from a finite set of possibilities. At its core, the Q...

(This article belongs to the Proceedings of The 7th Eurasia Conference on IoT, Communication and Engineering 2025 (ECICE 2025))
  • Article
  • Open Access
4 Citations
2,622 Views
17 Pages

Tailored Quantum Alternating Operator Ansätzes for Circuit Fault Diagnostics

  • Hannes Leipold,
  • Federico M. Spedalieri and
  • Eleanor Rieffel

28 September 2022

The quantum alternating operator ansatz (QAOA) and constrained quantum annealing (CQA) restrict the evolution of a quantum system to remain in a constrained space, often with a dimension much smaller than the whole Hilbert space. A natural question w...

(This article belongs to the Special Issue Artificial Intelligence for Fault Detection and Diagnosis)
  • Article
  • Open Access
696 Citations
29,075 Views
45 Pages

From the Quantum Approximate Optimization Algorithm to a Quantum Alternating Operator Ansatz

  • Stuart Hadfield,
  • Zhihui Wang,
  • Bryan O’Gorman,
  • Eleanor G. Rieffel,
  • Davide Venturelli and
  • Rupak Biswas

12 February 2019

The next few years will be exciting as prototype universal quantum processors emerge, enabling the implementation of a wider variety of algorithms. Of particular interest are quantum heuristics, which require experimentation on quantum hardware for t...

  • Article
  • Open Access
5 Citations
4,721 Views
16 Pages

17 January 2024

This paper presents a system for solving binary-valued linear equations using quantum computers. The system is called Mod2VQLS, which stands for Modulo 2 Variational Quantum Linear Solver. As far as we know, this is the first such proposal. The desig...

(This article belongs to the Section Quantum Science and Technology)
  • Article
  • Open Access
4 Citations
3,451 Views
11 Pages

Digital Quantum Simulation and Circuit Learning for the Generation of Coherent States

  • Ruilin Liu,
  • Sebastián V. Romero,
  • Izaskun Oregi,
  • Eneko Osaba,
  • Esther Villar-Rodriguez and
  • Yue Ban

25 October 2022

Coherent states, known as displaced vacuum states, play an important role in quantum information processing, quantum machine learning, and quantum optics. In this article, two ways to digitally prepare coherent states in quantum circuits are introduc...

(This article belongs to the Special Issue Quantum Control and Quantum Computing)
  • Article
  • Open Access
2,009 Views
20 Pages

Radar Signal Classification with Quantum Machine Learning: Ansatz Depth Impact on Expressibility

  • Gabriel F. Martinez,
  • Alberto Croci,
  • Francesco Drago,
  • Alessandro Niccolai,
  • Marco Mussetta and
  • Riccardo E. Zich

Radar systems serve as foundational components in both civil and military aerospace infrastructures. Modern radar must not only distinguish between detection and non-detection but must also classify detected objects. Signal processing increasingly in...

  • Communication
  • Open Access
5 Citations
5,468 Views
14 Pages

18 September 2023

Computational complexity reduction is at the basis of a new formulation of many-body quantum states according to tensor network ansatz, originally framed in one-dimensional lattices. In order to include long-range entanglement characterizing phase tr...

  • Article
  • Open Access
11 Citations
4,127 Views
11 Pages

Variational Quantum Circuits to Prepare Low Energy Symmetry States

  • Raja Selvarajan,
  • Manas Sajjan and
  • Sabre Kais

24 February 2022

We explore how to build quantum circuits that compute the lowest energy state corresponding to a given Hamiltonian within a symmetry subspace by explicitly encoding it into the circuit. We create an explicit unitary and a variationally trained unitar...

(This article belongs to the Section C: Physics)
  • Article
  • Open Access
1,083 Views
18 Pages

The selection of the right topology (ansatz) for a Variational Quantum Algorithm (VQA) is a complex task that usually involves deep knowledge of a particular problem. The importance of the selection is greater when we consider the current state of qu...

(This article belongs to the Special Issue New Trends in Computational Intelligence and Applications 2025)
  • Article
  • Open Access
2 Citations
4,820 Views
16 Pages

Understanding the capabilities of quantum computer devices and computing the required resources to solve realistic tasks remain critical challenges associated with achieving useful quantum computational advantage. We present a study aimed at reducing...

  • Article
  • Open Access
6 Citations
1,959 Views
9 Pages

Dimensionality Reduction with Variational Encoders Based on Subsystem Purification

  • Raja Selvarajan,
  • Manas Sajjan,
  • Travis S. Humble and
  • Sabre Kais

17 November 2023

Efficient methods for encoding and compression are likely to pave the way toward the problem of efficient trainability on higher-dimensional Hilbert spaces, overcoming issues of barren plateaus. Here, we propose an alternative approach to variational...

(This article belongs to the Section E: Applied Mathematics)
  • Article
  • Open Access
1,441 Views
40 Pages

Foreign-exchange decisions rest on hierarchically organized evidence whose latent structure is inadequately captured by Euclidean representations. Reinforcement-learning agents trained on flat embeddings inherit stability guarantees that do not trans...

(This article belongs to the Topic Artificial Intelligence Applications in Financial Technology, 2nd Edition)
  • Article
  • Open Access
863 Views
32 Pages

We investigate the structural limits of Variational Quantum Classifiers (VQC) for network anomaly detection in the Noisy Intermediate-Scale Quantum (NISQ) era. Using the official 20% research subset of NSL-KDD, we train a 4-qubit classifier that embe...

(This article belongs to the Section Network Security and Privacy)
  • Article
  • Open Access
153 Views
22 Pages

8 October 2026

Trajectory-derived scalars are often used to assess few-shot adaptation in variational quantum learning, but their associations may reflect optimization geometry rather than out-of-sample transfer. We audit parameter drift, an observable-variance pro...

(This article belongs to the Special Issue Advanced Computer Science and Intelligent Systems Innovations)