Machine Learning for Quantum Computing Specialists
Daniel Goldsmith, M M Hassan Mahmud
TL;DR
This paper provides a concise primer linking classical machine learning concepts to quantum computing contexts for specialists. It covers core ML techniques—supervised and unsupervised learning, kernel methods, PCA, deep learning, and GANs—and discusses how quantum feature maps and quantum kernels could enable new capabilities on NISQ devices. It emphasizes the current hardware limitations, such as high error rates and short decoherence times, and outlines the long horizon for fault-tolerant quantum computing to unlock scalable QML. By tying ML concepts to quantum notions with illustrative examples, the paper offers a practical entry point and signposts for further study.
Abstract
Quantum machine learning (QML) is a promising early use case for quantum computing. There has been progress in the last five years from theoretical studies and numerical simulations to proof of concepts. Use cases demonstrated on contemporary quantum devices include classifying medical images and items from the Iris dataset, classifying and generating handwritten images, toxicity screening, and learning a probability distribution. Potential benefits of QML include faster training and identification of feature maps not found classically. Although, these examples lack the scale for commercial exploitation, and it may be several years before QML algorithms replace the classical solutions, QML is an exciting area. This article is written for those who already have a sound knowledge of quantum computing and now wish to gain a basic overview of the terminology and some applications of classical machine learning ready to study quantum machine learning. The reader will already understand the relevant relevant linear algebra, including Hilbert spaces, a vector space with an inner product.
