Quantum Machine Learning algorithms generally rely on hybrid implementation with a classical learning loop running on a CPU and small quantum circuits running on a Quantum Processing Unit (QPU) for serialized processing batches of data. Considering the scarcity of quantum resources, parallelizing the execution of multiple instances of small quantum circuits instead of allocating a single circuit would better use quantum hardware resources. However, exploiting all available qubits in QPUs could result in a noisier operating condition and disrupt or slow the learning mechanism. This paper investigates the parallelization of QML algorithms on QPU for data clustering based on trainable generative models. We design a parallel macro-circuit with the Qiskit framework and measure their performance on an IBM superconducting quantum computer. A theoretical performance model is then proposed to determine the expected level of acceleration. Finally, we measure the impact of the QPU's occupancy on the loss functions of our QML algorithm, enabling us to identify the most reliable and exploitable acceleration range.
Quantum Machine Learning algorithms generally rely on hybrid implementation with a classical learning loop running on a CPU and small quantum circuits running on a Quantum Processing Unit (QPU) for serialized processing batches of data. Considering the scarcity of quantum resources, parallelizing the execution of multiple instances of small quantum circuits instead of allocating a single circuit would better use quantum hardware resources. However, exploiting all available qubits in QPUs could result in a noisier operating condition and disrupt or slow the learning mechanism. This paper investigates the parallelization of QML algorithms on QPU for data clustering based on trainable generative models. We design a parallel macro-circuit with the Qiskit framework and measure their performance on an IBM superconducting quantum computer. A theoretical performance model is then proposed to determine the expected level of acceleration. Finally, we measure the impact of the QPU's occupancy on the loss functions of our QML algorithm, enabling us to identify the most reliable and exploitable acceleration range.
This paper addresses the critical limitations of existing quantum machine learning (QML) frameworks concerning scalability, specifically their inability to efficiently handle large-scale quantum datasets. We propose a novel, scalable QML framework designed to effectively process these datasets and accelerate the training and inference of quantum machine learning algorithms. The core mechanism leverages quantum parallelism, constructing a framework capable of handling increased complexity. This work represents a significant advancement by directly tackling the scalability bottleneck in QML, establishing a foundational element for future developments in the field. The framework utilizes a modular architecture incorporating optimized quantum circuits and classical processing units for data preparation, model training, and result evaluation. The key innovation lies in the dynamic partitioning of quantum computations across multiple quantum processors, coupled with sophisticated data encoding strategies to mitigate the effects of qubit decoherence and limited qubit counts. This approach allows for the parallel execution of complex quantum algorithms, drastically reducing computational overhead and enabling the training of larger and more sophisticated models. We demonstrate the potential of this framework through theoretical analysis and algorithmic design, highlighting its advantages over traditional, monolithic QML implementations.
Quantum computers are the next evolution of computing hardware. Quantum devices are being exposed through the same familiar cloud platforms used for classical computers, and enabling seamless execution of hybrid applications that combine quantum and classical components. Quantum devices vary in features, e.g., number of qubits, quantum volume, CLOPS, noise profile, queuing delays and resource cost. So, it may be useful to split hybrid workloads with either large quantum circuits or a large number of quantum circuits, into smaller units. In this paper, we profile two workload splitting techniques on IBM's Quantum Cloud: (1) Circuit parallelization, to split one large circuit into multiple smaller ones, and (2) Data parallelization to split a large number of circuits that run on one device to smaller batches of circuits that run on concurrently on multiple devices. These can improve the utilization of heterogeneous quantum hardware, but involve trade-offs. We evaluate these techniques on two key algorithmic classes: Variational Quantum Eigensolver (VQE) and Quantum Support Vector Machine (QSVM), and measure the impact on quality of the result, circuit execution times, quantum resource usage, and processing overheads, relative to a baseline without such parallelization. The results are obtained on real hardware and complemented by simulations. We see that (1) VQE with circuit cutting is ~ 39% better in ground state estimation than the uncut version, and (2) QSVM that combines data parallelization with a reduced feature set yields upto 3 ×improvement in quantum workload execution time and reduces quantum resource use by 3 ×, while providing comparable accuracy. Error mitigation can improve the accuracy by ≈ 7% and reduce resource footprint by ≈4% compared to the best case among the considered scenarios.
Quantum machine learning (QML) holds immense promise for revolutionizing various fields, including drug discovery, materials science, and financial modeling. However, the training of complex QML models is inherently challenging due to the inherent limitations of quantum hardware. This paper presents an algorithmic parallelism framework designed to accelerate the training process of quantum machine learning models, focusing on both speed and stability. We propose a novel approach that leverages asynchronous quantum computing principles and distributed training techniques to effectively parallelize the computation, mitigating the limitations of a single quantum processor. The core mechanism involves a carefully orchestrated execution schedule, optimized for both quantum fidelity and classical computation. This work addresses a critical bottleneck in QML performance, presenting a promising path towards practical quantum machine learning applications.
We propose a Quantum Machine Learning (QML) framework that applies the core design principle of quantum algorithms–superposition, oracle, and interference–to accelerate training. Building on the structural analogy between feature extraction in foundational quantum algorithms and parameter optimization in QML, we reformulate the training process to leverage quantum parallelism: all training samples are encoded into a quantum superposition, processed through a parameterized quantum circuit, and classified via an interferometer module that implements quantum interference across the dataset. This architectural reformulation reduces the theoretical complexity of loss function evaluation from O(N2) in conventional QML training to O ( N ), where N is the dataset size. Numerical simulations on multiple binary and multi-class classification datasets (with up to N=128 samples) demonstrate that our method achieves classification accuracies comparable to conventional circuits while reducing the number of quantum circuit executions per cost function evaluation from N to 1. This represents a near N -fold reduction in quantum overhead per training iteration, reducing the required circuit executions without loss of accuracy. These results highlight the potential of quantum algorithmic design principles as a scalable pathway to efficient QML implementations.
Machine Learning (ML) has been widely applied across numerous domains due to its ability to automatically identify informative patterns from data for various tasks. The availability of large-scale data and advanced computational power enables the development of sophisticated models and training strategies, leading to state-of-the-art performance, but it also introduces substantial challenges. Quantum Computing (QC), which exploits quantum mechanisms for computation, has attracted growing attention and significant global investment as it may address these challenges. Consequently, Quantum Machine Learning (QML), the integration of these two fields, has received increasing interest, with a notable rise in related studies in recent years. We are motivated to review these existing contributions regarding quantum circuit-based learning models for classical data analysis and highlight the identified potentials and challenges of this technique. Specifically, we focus not only on QML models, both kernel-based and neural network-based, but also on recent explorations of their integration with classical machine learning layers within hybrid frameworks. Moreover, we examine both theoretical analysis and empirical findings to better understand their capabilities, and we also discuss the efforts on noise-resilient and hardware-efficient QML that could enhance its practicality under current hardware limitations. In addition, we cover several emerging paradigms for advanced quantum circuit design and highlight the adaptability of QML across representative application domains. This study aims to provide an overview of the contributions made to bridge quantum computing and machine learning, offering insights and guidance to support its future development and pave the way for broader adoption in the coming years.
Today's quantum processors have tens to hundreds of physical qubits, but reliable execution of arbitrary circuits remains limited to fewer than 30 entangled qubits across hardware modalities. Building upon prior work, we introduce an error- and topology-aware method for mapping multiple independent circuits onto disjoint regions of a single large-scale QPU for parallel circuit execution. For applications with many similarly sized circuits, such as observable estimation for Hamiltonian simulation, this approach can reduce billed QPU execution time, with ideal speedup proportional to the number of usable partitions. We demonstrate the approach on IBM's 156-qubit ibm_boston processor using standard QED-C benchmark and Hamiltonian-based observable-estimation workloads. Compared with standard sequential execution, parallel execution reduces billed execution time by 3.5-5.5x while retaining 83-92% of the sequential fidelity. We further evaluate the scaling of parallel circuit execution using GPU-accelerated classical simulation, distributing measurement circuits across GPUs via MPI. Using CUDA-Q on the NERSC Perlmutter system, we achieve up to 13.8x speedup on 16 GPUs (86% parallel efficiency) for an H2 electronic-structure simulation, with scaling evaluated across multiple Hamiltonians and circuit counts. These results provide an indication of the performance ceiling that parallel execution on future quantum hardware may eventually approach. Both execution modes are implemented as a runtime option within the QED-C Application-Oriented Benchmark suite. Together, the results show that circuit-level parallelism can reduce execution cost on current quantum hardware and simulation time on GPU clusters, with the potential for greater benefits as device quality and qubit counts increase.