ABSTRACT Quantum computing is poised to transform computational paradigms across science and industry. As the field evolves, it can benefit from established classical methodologies, including promising paradigms such as Transfer of Knowledge (ToK). This work serves as a brief, self‐contained reference for ToK, unifying its core principles under a single formal framework. We introduce a joint notation that consolidates and extends prior work in Transfer Learning and Transfer Optimisation, bridging traditionally separate research lines and enabling a common language for knowledge reuse. Building on this foundation, we classify existing ToK strategies and principles into a structured taxonomy that helps researchers position their methods within a broader conceptual map. We then extend key transfer protocols to quantum computing, introducing two novel use cases—reverse annealing and multitasking Quantum Approximate Optimization Algorithm (QAOA)—alongside a sequential Variational Quantum Eigensolver (VQE) approach that supports and validates prior findings. These examples highlight ToK's potential to improve performance and generalisation in quantum algorithms. Finally, we outline challenges and opportunities for integrating ToK into quantum computing, emphasising its role in reducing resource demands and accelerating problem‐solving. This work lays the groundwork for future synergies between classical and quantum computing through a shared, transferable knowledge framework.
ABSTRACT Quantum computing is poised to transform computational paradigms across science and industry. As the field evolves, it can benefit from established classical methodologies, including promising paradigms such as Transfer of Knowledge (ToK). This work serves as a brief, self‐contained reference for ToK, unifying its core principles under a single formal framework. We introduce a joint notation that consolidates and extends prior work in Transfer Learning and Transfer Optimisation, bridging traditionally separate research lines and enabling a common language for knowledge reuse. Building on this foundation, we classify existing ToK strategies and principles into a structured taxonomy that helps researchers position their methods within a broader conceptual map. We then extend key transfer protocols to quantum computing, introducing two novel use cases—reverse annealing and multitasking Quantum Approximate Optimization Algorithm (QAOA)—alongside a sequential Variational Quantum Eigensolver (VQE) approach that supports and validates prior findings. These examples highlight ToK's potential to improve performance and generalisation in quantum algorithms. Finally, we outline challenges and opportunities for integrating ToK into quantum computing, emphasising its role in reducing resource demands and accelerating problem‐solving. This work lays the groundwork for future synergies between classical and quantum computing through a shared, transferable knowledge framework.
Hybrid quantum-classical algorithms have gained attention as a promising strategy to harness the advantages of both quantum and classical computing for machine learning applications. This review delves into the potential of these algorithms to address the limitations inherent in purely classical or quantum methods, offering a thorough overview of the current landscape in this area. We cover the basics of quantum computing, such as qubits, superposition, and entanglement, and emphasize the challenges that both quantum and classical computing face in the realm of machine learning. Various hybrid frameworks, including quantum-classical neural networks, quantum-enhanced optimization algorithms, and quantum feature maps, are explored in depth. We examine specific hybrid algorithms, like the variational quantum eigensolver (VQE) and the quantum approximate optimization algorithm (QAOA), assessing their potential to enhance data preprocessing, feature selection, model training, and inference. The role of quantum-inspired algorithms in bridging the gap between quantum and classical methods is also discussed. We investigate the scalability of hybrid approaches and their potential to capitalize on future advancements in quantum hardware, while considering implementation challenges such as quantum error correction and noise mitigation. The implications of these algorithms for privacy, security, fairness, and interpretability in machine learning are analyzed. Finally, we consider the potential impact of hybrid quantum-classical algorithms on various industries and their integration with other emerging technologies. This review offers a comprehensive perspective on the current state and future directions of this rapidly evolving field.
This chapter investigates the application of quantum computing to optimization, a field traditionally dominated by classical methods but increasingly limited by computational demands in tackling complex, large-scale problems. The discussion focuses on quantum optimization techniques, particularly variational quantum algorithms like the Quantum Approximate Optimization Algorithm (QAOA) and the variational quantum eigensolver (VQE), along with quantum annealing (QA), a process inspired by physical annealing that leverages quantum tunnelling and superposition. The chapter also explores the integration of quantum approaches within machine learning frameworks, where quantum algorithms can potentially accelerate model training and enhance capabilities. Additionally, it presents practical applications and challenges associated with these quantum algorithms, covering their effectiveness on noisy intermediate-scale quantum (NISQ) devices and the evolving landscape of quantum hardware. This chapter concludes with insights into quantum optimization's future potential to address optimization and machine learning challenges that are currently intractable for classical methods, marking a significant shift in computational science.
This paper explores the potential of integrating quantum annealing principles with quantum algorithms to develop efficient quantum computing solutions. The core concept revolves around a novel algorithm termed "Quantum Annealing Algorithm," which leverages the annealing process to optimize the parameters of quantum algorithms, ultimately enhancing their computational efficiency. This work details the theoretical framework, outlining the mathematical formulation of the algorithm and its key components. We present a methodology for mapping classical optimization problems onto a quantum annealing framework, and discuss strategies for managing the trade-offs between annealing speed and solution quality. The proposed approach offers a potentially transformative method for accelerating quantum computations, particularly for problems exhibiting complex, rugged energy landscapes. The focus remains on the theoretical design and potential benefits, without empirical experimental validation.
Quantum computing and artificial intelligence (AI) are two rapidly evolving technologies poised to redefine the future of computation and decision-making.The two fields unite under the name Quantum Artificial Intelligence (QAI) or Quantum Intelligence, which enables a transformative approach to problem-solving through the fusion of AI mental functions with quantum computing capabilities.This paper provides a comprehensive review of the current landscape, highlighting the opportunities and challenges in integrating quantum computing with AI systems.The research investigates current developments in quantum machine learning, quantum neural networks, and hybrid quantum-classical systems, which show promise for achieving rapid performance improvements and enhanced scalability and data processing capabilities.At the same time, it identifies critical barriers, including hardware limitations, algorithmic complexity, data encoding issues, and the lack of standardization in frameworks.The review further explores future directions, including the role of explainable AI, error correction, and interdisciplinary research in achieving practical quantum-AI synergy.By analyzing both the technological potential and the practical constraints, this paper aims to outline a roadmap for advancing quantum intelligence as a transformative force in next-generation computational paradigms.
Quantum Computing and Artificial Intelligence (AI) are two transformative paradigms whose convergence holds immense potential to reshape computational science. This chapter explores the foundational principles of quantum computation and machine learning, emphasizing their interplay in addressing classically intractable problems. A systematic exposition of key quantum algorithms, such as Shor's factoring algorithm, Grover's algorithm, and the Variational Quantum Eigensolver (VQE), and particular focus is placed on variational quantum algorithms (VQAs), which have emerged as central tools in the NISQ era due to their hybrid quantum-classical nature. The experimental investigation conducted through VQE demonstrates the capability of expectation value minimization for approximating ground-state energies, with fidelity analysis offering insight into the accuracy and stability of the method. The chapter concludes with a discussion of open challenges and outlines future research directions, emphasizing error mitigation, algorithmic innovation, and the co-design of hardware and software.
The convergence of machine learning (ML) and quantum computing is quickly becoming a game-changing new frontier in computational science. The most intriguing area of overlap may be quantum optimization, which seeks to reduce the exponentially increasing complexity and computational cost of ML algorithms. As they grow larger and more complicated, traditional optimization methods, particularly in high-dimensional and non-convex space, will inevitably hit performance limits. Quantum optimization is the whole new paradigm that leverages quantum mechanical effects like superposition, entanglement, and tunnelling to explore solution spaces more efficiently. The chapter outlines the theory, practice, and potential of hybrid quantum-classical optimization algorithms for machine learning. The most brilliant research direction in the current NISQ (noisy intermediate-scale quantum) era is mixed systems leveraging classical computing capability augmented by quantum capacity. In such designs, computationally intensive subroutines like optimization for global optima or escape from local minima are left to quantum processors and data preprocessing, iterative refinement, and model testing are performed by classical processors. We start by defining the fundamental principles of quantum computing and acquainting readers with the fundamentals like qubits, quantum gates, and quantum circuits. These are the building blocks for quantum algorithms, which hopefully can be utilized for optimization, for example, the QAOA (quantum approximate optimization algorithm), the VQE (variational quantum Eigensolver), and quantum annealing. They all build to optimize the problems in some way differently: QAOA through parameterized quantum circuits, VQE through approximations of ground states of the Hamiltonians, and quantum annealing through quantum evolution to low-energy solutions. We then form a loop between these quantum algorithms and regular machine learning tasks. Optimization impacts virtually all ML phases, from training neural networks, where one reduces loss functions; feature selection, where one aims to discover the most relevant subset of input variables; and hyperparameter optimization, which often involves expensive search procedures over extremely large combinatorial spaces. Quantum optimization techniques can therefore, in principle, accelerate such procedures through computational complexity reduction and enhancing solutions over challenging landscapes. Realistic simulations and case studies emphasize the degree to which hybrid quantum-classical algorithms have been employed in solving ML problems, that is, QSVMs, quantum-enhanced clustering, and quantum reinforcement learning. Despite their experimental nature, these applications already show encouraging results in terms of improved performance metrics as well as reduction in time-to-solution compared to classical-only solutions. Notwithstanding that, this new field is not bereft of real challenges. Quantum hardware suffers from hard limits on qubit fidelity, decoherence, and scalability in the current times. Furthermore, quantum circuit integration into broad ML pipelines requires novel architectures and software platforms. As a counter to those issues, this chapter surveys recent advances in quantum programming languages, simulators, and hybrid platforms like PennyLane, Qiskit, and TensorFlow Quantum. We conclude by looking to the future possibility that quantum optimization will revolutionize the machine learning landscape. As hardware improves and algorithmic complexity increases, the possibility of quantum-powered learning systems solving hard problems becomes increasingly accessible. From speeding up deep network training to enabling new types of unsupervised learning, quantum optimization holds the potential to recast computational tractability in machine learning. This chapter is an all-encompassing introduction and state-of-the-art work for students, researchers, and practitioners interested in using quantum optimization for practical ML applications. It sets the foundation for understanding how to pursue hybrid approaches (how they may be applied today in the real world and bracing oneself for disruption in the future).