The rapid advancement of quantum computing (QC) and machine learning (ML) has given rise to the burgeoning field of quantum machine learning (QML), aiming to capitalize on the strengths of quantum computing to propel ML forward. Despite its promise, crafting effective QML models necessitates profound expertise to strike a delicate balance between model intricacy and feasibility on Noisy Intermediate-Scale Quantum (NISQ) devices. While complex models offer robust representation capabilities, their extensive circuit depth may impede seamless execution on extant noisy quantum platforms. In this paper, we address this quandary of QML model design by employing deep reinforcement learning to explore proficient QML model architectures tailored for designated supervised learning tasks. Specifically, our methodology involves training an RL agent to devise policies that facilitate the discovery of QML models without predetermined ansatz. Furthermore, we integrate an adaptive mechanism to dynamically adjust the learning objectives, fostering continuous improvement in the agent's learning process. Through extensive numerical simulations, we illustrate the efficacy of our approach within the realm of classification tasks. Our proposed method successfully identifies VQC architectures capable of achieving high classification accuracy while minimizing gate depth. This pioneering approach not only advances the study of AI-driven quantum circuit design but also holds significant promise for enhancing performance in the NISQ era.
The rapid advancement of quantum computing (QC) and machine learning (ML) has given rise to the burgeoning field of quantum machine learning (QML), aiming to capitalize on the strengths of quantum computing to propel ML forward. Despite its promise, crafting effective QML models necessitates profound expertise to strike a delicate balance between model intricacy and feasibility on Noisy Intermediate-Scale Quantum (NISQ) devices. While complex models offer robust representation capabilities, their extensive circuit depth may impede seamless execution on extant noisy quantum platforms. In this paper, we address this quandary of QML model design by employing deep reinforcement learning to explore proficient QML model architectures tailored for designated supervised learning tasks. Specifically, our methodology involves training an RL agent to devise policies that facilitate the discovery of QML models without predetermined ansatz. Furthermore, we integrate an adaptive mechanism to dynamically adjust the learning objectives, fostering continuous improvement in the agent's learning process. Through extensive numerical simulations, we illustrate the efficacy of our approach within the realm of classification tasks. Our proposed method successfully identifies VQC architectures capable of achieving high classification accuracy while minimizing gate depth. This pioneering approach not only advances the study of AI-driven quantum circuit design but also holds significant promise for enhancing performance in the NISQ era.
Quantum computing has promised significant improvement in solving difficult computational tasks over classical computers. Designing quantum circuits for practical use, however, is not a trivial objective and requires expert-level knowledge. To aid this endeavor, this paper proposes a machine learning-based method to construct quantum circuit architectures. Previous works have demonstrated that classical deep reinforcement learning (DRL) algorithms can successfully construct quantum circuit architectures without encoded physics knowledge. However, these DRL-based works are not generalizable to settings with changing device noises, thus requiring considerable amounts of training resources to keep the RL models up-to-date. With this in mind, we incorporated continual learning to enhance the performance of our algorithm. In this paper, we present the Probabilistic Policy Reuse with deep Q-learning (PPR-DQL) framework to tackle this circuit design challenge. By conducting numerical simulations over various noise patterns, we demonstrate that the RL agent with PPR was able to find the quantum gate sequence to generate the two-qubit Bell state faster than the agent that was trained from scratch. The proposed framework is general and can be applied to other quantum gate synthesis or control problems -- including the automatic calibration of quantum devices.
The emergence of quantum reinforcement learning (QRL) is propelled by advancements in quantum computing (QC) and machine learning (ML), particularly through quantum neural networks (QNN) built on variational quantum circuits (VQC). These advancements have proven successful in addressing sequential decision-making tasks. However, constructing effective QRL models demands significant expertise due to challenges in designing quantum circuit architectures, including data encoding and parameterized circuits, which profoundly influence model performance. In this paper, we propose addressing this challenge with differentiable quantum architecture search (DiffQAS), enabling trainable circuit parameters and structure weights using gradient-based optimization. Furthermore, we enhance training efficiency through asynchronous reinforcement learning (RL) methods facilitating parallel training. Through numerical simulations, we demonstrate that our proposed DiffQAS-QRL approach achieves performance comparable to manually-crafted circuit architectures across considered environments, showcasing stability across diverse scenarios. This methodology offers a pathway for designing QRL models without extensive quantum knowledge, ensuring robust performance and fostering broader application of QRL.
The convergence of quantum computing and artificial intelligence presents profound opportunities but faces significant hurdles, particularly in the Noisy Intermediate-Scale Quantum (NISQ) era. Quantum Machine Learning (QML) algorithms, while promising, exhibit sensitivity to noise and scalability challenges, hindering the demonstration of practical quantum advantage. Concurrently, Quantum Error Correction (QEC), essential for fault tolerance, imposes substantial resource overheads and is often developed generically, without specific adaptation to the target application's error sensitivity. This paper reviews the current state of the intersection of AI and quantum computing, examining both QML paradigms, e.g., Variational Quantum Algorithms, Quantum Kernels, and the burgeoning use of AI to enhance quantum computing itself, e.g., quantum control, QEC decoding, circuit design. A critical gap identified is the lack of frameworks that systematically co-design QML algorithms and QEC protocols adaptively. To address this, a novel framework is proposed based on Reinforcement Learning (RL). This framework employs an RL agent to dynamically adjust both the QML circuit architecture, e.g., VQC ansatz, and QEC parameters, e.g., decoding strategy, measurement frequency, based on observed application performance and estimated error characteristics. This adaptive co-design loop aims to optimize the trade-off between QML performance and QEC overhead, enhancing noise resilience and resource efficiency. The potential advantages, feasibility, and limitations of this approach are discussed, alongside with future research directions aimed at realizing robust and practical Quantum AI.
With the evolution of technology, the need to solve complex computational problems like machine learning and deep learning has shot up. However, even the most powerful classical supercomputers find it difficult to execute these tasks. Advancements in quantum computing are leading researchers and tech-giants who strive for better quantum circuits to do machine learning tasks. Current works on Quantum Machine Learning (QML) ensure less memory consumption and reduced model parameters. However, it is strenuous to simulate the classical deep learning approach on existing quantum computing devices due to the inflexibility of Deep quantum circuits. Consequently, designing viable quantum algorithms for QML for noisy intermediate-scale quantum (NISQ) devices is essential. The proposed work aims to explore Variational Quantum Circuits (VQC) for Deep Q network-based Reinforcement Learning by remodeling the target network and experience replay into a representation of VQC. In addition, to the reduction in model parameters, quantum information encoding schemes are used to achieve better results than classical neural networks. VQCs are employed for policyselection and decision-making reinforcement learning by approximating the deep Q-value function with target network and experience replay.
Quantum Machine Learning (QML) is rapidly emerging as a frontier field, combining quantum computing and artificial intelligence to address fundamental challenges in learning scalability and adaptability. This paper explores how the principles of quantum mechanics can be harnessed-particularly through variational quantum circuits (VQCs)-to design efficient QML architectures suitable for noisy intermediate-scale quantum (NISQ) devices. We present recent advancements including Quantum Federated Learning (QFL) for privacy-preserving distributed intelligence, Quantum Long Short-Term Memory (QL-STM) networks for sequential pattern modeling, and Quantum Reinforcement Learning (QRL) for dynamic decision-making. Furthermore, we introduce the Quantum Fast Weight Programmer (QFWP), a mechanism for rapid, context-driven parameter adaptation to support meta-learning in quantum systems. We also discuss differentiable quantum architecture search (DiffQAS) as a means of automatically optimizing quantum circuit structures. Despite limitations in quantum hardware-such as decoherence, noise, and limited qubit counts-we review mitigation strategies including hybrid quantum-classical training, error-aware optimization, and scalable architectural design. This work outlines a forward-looking framework for building scalable, adaptive, and trustworthy Quantum AI systems.
As the technology of quantum computers experienced major advancements in recent years, Quantum computing (QC) has also naturally received an unprecedented amount of attention and the number of research on the topic has greatly increased as well. This is because compared to classical computing, QC is able to solve complex problems quickly and possess impressive computational capabilities. One of the fields which can exploit the strengths of QC is quantum machine learning (QML). QML integrates the field of QC and machine learning by applying QC to various areas of machine learning e.g., deep learning, reinforcement learning, and distributed learning. Despite the noise intermediate scale quantum (NISQ) limitation of QC, QML models still show superior performance compared to their classical counterparts by leveraging the strengths of QC. This has been thoroughly corroborated via extensive simulation results in many works which demonstrate the full potential and importance of QML. Therefore, in this paper, we aim to explore various QML methodologies e.g., quantum deep learning, quantum deep reinforcement learning, and quantum distributed learning. Furthermore, the model structures of each methodology will be discussed, highlighting the possibilities and limitations of each model. Finally, the direction of future works of QML research will be discussed as well.