Empowering complex-valued data classification with the variational quantum classifier

The evolution of quantum computers has encouraged research into how to handle tasks with significant computation demands in the past few years. Due to the unique advantages of quantum parallelism and entanglement, various types of quantum machine learning (QML) methods, especially variational quantu...

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Main Authors: Jianing Chen, Yan Li
Format: Article
Language:English
Published: Frontiers Media S.A. 2024-02-01
Series:Frontiers in Quantum Science and Technology
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/frqst.2024.1282730/full
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author Jianing Chen
Yan Li
author_facet Jianing Chen
Yan Li
author_sort Jianing Chen
collection DOAJ
description The evolution of quantum computers has encouraged research into how to handle tasks with significant computation demands in the past few years. Due to the unique advantages of quantum parallelism and entanglement, various types of quantum machine learning (QML) methods, especially variational quantum classifiers (VQCs), have attracted the attention of many researchers and have been developed and evaluated in numerous scenarios. Nevertheless, most of the research on VQCs is still in its early stages. For instance, as a consequence of the mathematical constraints imposed by the properties of quantum states, the majority of research has not fully taken into account the impact of data formats on the performance of VQCs. In this paper, considering a significant number of data in the real world exist in the form of complex numbers, i.e., phasor data in power systems and the result of Fourier transform on image processing, we develop two categories of data encoding methods, including coupling data encoding and splitting data encoding. This paper features the coupling data encoding method to encode complex-valued data in a way of amplitude encoding. By leveraging the property of quantum states living in a complex Hilbert space, the complex-valued data is embedded into the amplitude of quantum states to comprehensively characterize complex-valued information. Optimizers will be utilized to iteratively tune a parameterized ansatz, with the aim of minimizing the value of loss functions defined with respect to the specific classification task. In addition, distinct factors in VQCs have been explored in detail to investigate the performance of VQCs, including data encoding methods, loss functions, and optimizers. The experimental result shows that the proposed data encoding method outperforms other typical encoding methods on a given classification task. Moreover, different loss functions are tested, and the capability of finding the minimum value is evaluated for gradient-free and gradient-based optimizers, which provides valuable insights and guidelines for practical implementations.
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spelling doaj.art-23ebf8e53fcb42328085a0b98c5bbca32024-02-07T04:35:17ZengFrontiers Media S.A.Frontiers in Quantum Science and Technology2813-21812024-02-01310.3389/frqst.2024.12827301282730Empowering complex-valued data classification with the variational quantum classifierJianing ChenYan LiThe evolution of quantum computers has encouraged research into how to handle tasks with significant computation demands in the past few years. Due to the unique advantages of quantum parallelism and entanglement, various types of quantum machine learning (QML) methods, especially variational quantum classifiers (VQCs), have attracted the attention of many researchers and have been developed and evaluated in numerous scenarios. Nevertheless, most of the research on VQCs is still in its early stages. For instance, as a consequence of the mathematical constraints imposed by the properties of quantum states, the majority of research has not fully taken into account the impact of data formats on the performance of VQCs. In this paper, considering a significant number of data in the real world exist in the form of complex numbers, i.e., phasor data in power systems and the result of Fourier transform on image processing, we develop two categories of data encoding methods, including coupling data encoding and splitting data encoding. This paper features the coupling data encoding method to encode complex-valued data in a way of amplitude encoding. By leveraging the property of quantum states living in a complex Hilbert space, the complex-valued data is embedded into the amplitude of quantum states to comprehensively characterize complex-valued information. Optimizers will be utilized to iteratively tune a parameterized ansatz, with the aim of minimizing the value of loss functions defined with respect to the specific classification task. In addition, distinct factors in VQCs have been explored in detail to investigate the performance of VQCs, including data encoding methods, loss functions, and optimizers. The experimental result shows that the proposed data encoding method outperforms other typical encoding methods on a given classification task. Moreover, different loss functions are tested, and the capability of finding the minimum value is evaluated for gradient-free and gradient-based optimizers, which provides valuable insights and guidelines for practical implementations.https://www.frontiersin.org/articles/10.3389/frqst.2024.1282730/fullquantum machine learningvariational quantum classifiercomplex-valued datacoupling data encodingsplitting data encodingloss function
spellingShingle Jianing Chen
Yan Li
Empowering complex-valued data classification with the variational quantum classifier
Frontiers in Quantum Science and Technology
quantum machine learning
variational quantum classifier
complex-valued data
coupling data encoding
splitting data encoding
loss function
title Empowering complex-valued data classification with the variational quantum classifier
title_full Empowering complex-valued data classification with the variational quantum classifier
title_fullStr Empowering complex-valued data classification with the variational quantum classifier
title_full_unstemmed Empowering complex-valued data classification with the variational quantum classifier
title_short Empowering complex-valued data classification with the variational quantum classifier
title_sort empowering complex valued data classification with the variational quantum classifier
topic quantum machine learning
variational quantum classifier
complex-valued data
coupling data encoding
splitting data encoding
loss function
url https://www.frontiersin.org/articles/10.3389/frqst.2024.1282730/full
work_keys_str_mv AT jianingchen empoweringcomplexvalueddataclassificationwiththevariationalquantumclassifier
AT yanli empoweringcomplexvalueddataclassificationwiththevariationalquantumclassifier