Many quantum algorithms for machine learning require access to classical data in superposition. However, for many natural data sets and algorithms, the overhead required to load the data set in superposition can erase any potential quantum speedup over classical algorithms. Recent work by Harrow introduces a new paradigm in hybrid quantum-classical computing to address this issue, relying on coresets to minimize the data loading overhead of quantum algorithms. We investigated using this paradigm to perform k-means clustering on near-term quantum computers, by casting it as a QAOA optimization instance over a small coreset. We used numerical simulations to compare the performance of this approach to classical k-means clustering. We were able to find data sets with which coresets work well relative to random sampling and where QAOA could potentially outperform standard k-means on a coreset. However, finding data sets where both coresets and QAOA work well—which is necessary for a quantum advantage over k-means on the entire data set—appears to be challenging.Many quantum algorithms for machine learning require access to classical data in superposition. However, for many natural data sets and algorithms, the overhead required to load the data set in superposition can erase any potential quantum speedup over classical algorithms. Recent work by Harrow introduces a new paradigm in hybrid quantum-classical computing to address this issue, relying on coresets to minimize the data loading overhead of quantum algorithms. We investigated using this paradigm to perform k-means clustering on near-term quantum computers, by casting it as a QAOA optimization instance over a small coreset. We used numerical simulations to compare the performance of this approach to classical k-means clustering. We were able to find data sets with which coresets work well relative to random sampling and where QAOA could potentially outperform standard k-means on a coreset. However, finding data sets where both coresets and QAOA work well—which is necessary for a quantum advantage over k-means on the entire data set—appears to be challenging.

Jul 15, 202125 citations

Big data applications on small quantum computers

Boniface Yogendran, Charlton, Daniel, Miriam Beddig +2 more

Current quantum hardware prohibits any direct use of large classical datasets. Coresets allow for a succinct description of these large datasets and their solution in a computational task is competitive with the solution on the original dataset. The method of combining coresets with small quantum computers to solve a given task that requires a large number of data points was first introduced by Harrow [arXiv:2004.00026]. In this paper, we apply the coreset method in three different well-studied classical machine learning problems, namely Divisive Clustering, 3-means Clustering, and Gaussian Mixture Model Clustering. We provide a Hamiltonian formulation of the aforementioned problems for which the number of qubits scales linearly with the size of the coreset. Then, we evaluate how the variational quantum eigensolver (VQE) performs on these problems and demonstrate the practical efficiency of coresets when used along with a small quantum computer. We perform noiseless simulations on instances of sizes up to 25 qubits on CUDA Quantum and show that our approach provides comparable performance to classical solvers.Current quantum hardware prohibits any direct use of large classical datasets. Coresets allow for a succinct description of these large datasets and their solution in a computational task is competitive with the solution on the original dataset. The method of combining coresets with small quantum computers to solve a given task that requires a large number of data points was first introduced by Harrow [arXiv:2004.00026]. In this paper, we apply the coreset method in three different well-studied classical machine learning problems, namely Divisive Clustering, 3-means Clustering, and Gaussian Mixture Model Clustering. We provide a Hamiltonian formulation of the aforementioned problems for which the number of qubits scales linearly with the size of the coreset. Then, we evaluate how the variational quantum eigensolver (VQE) performs on these problems and demonstrate the practical efficiency of coresets when used along with a small quantum computer. We perform noiseless simulations on instances of sizes up to 25 qubits on CUDA Quantum and show that our approach provides comparable performance to classical solvers.

arXiv:2402.01529Feb 2, 20243 citations

Small quantum computers and large classical data sets

Aram W. Harrow

We introduce hybrid classical-quantum algorithms for problems involving a large classical data set X and a space of models Y such that a quantum computer has superposition access to Y but not X. These algorithms use data reduction techniques to construct a weighted subset of X called a coreset that yields approximately the same loss for each model. The coreset can be constructed by the classical computer alone, or via an interactive protocol in which the outputs of the quantum computer are used to help decide which elements of X to use. By using the quantum computer to perform Grover search or rejection sampling, this yields quantum speedups for maximum likelihood estimation, Bayesian inference and saddle-point optimization. Concrete applications include k-means clustering, logistical regression, zero-sum games and boosting.We introduce hybrid classical-quantum algorithms for problems involving a large classical data set X and a space of models Y such that a quantum computer has superposition access to Y but not X. These algorithms use data reduction techniques to construct a weighted subset of X called a coreset that yields approximately the same loss for each model. The coreset can be constructed by the classical computer alone, or via an interactive protocol in which the outputs of the quantum computer are used to help decide which elements of X to use. By using the quantum computer to perform Grover search or rejection sampling, this yields quantum speedups for maximum likelihood estimation, Bayesian inference and saddle-point optimization. Concrete applications include k-means clustering, logistical regression, zero-sum games and boosting.

arXiv:2004.00026Mar 31, 202030 citations

Performance analysis of coreset selection for quantum implementation of K-Means clustering algorithm

Fanzhe Qu, Sarah Erfani, Muhammad Usman

Quantum computing is anticipated to offer immense computational capabilities which could provide efficient solutions to many data science problems. However, the current generation of quantum devices are small and noisy, which makes it difficult to process large data sets relevant for practical problems. Coreset selection aims to circumvent this problem by reducing the size of input data without compromising the accuracy. Recent work has shown that coreset selection can help to implement quantum K-Means clustering problem. However, the impact of coreset selection on the performance of quantum K-Means clustering has not been explored. In this work, we compare the relative performance of two coreset techniques (BFL16 and ONESHOT), and the size of coreset construction in each case, with respect to a variety of data sets and layout the advantages and limitations of coreset selection in implementing quantum algorithms. We also investigated the effect of depolarisation quantum noise and bit-flip error, and implemented the Quantum AutoEncoder technique for surpassing the noise effect. Our work provides useful insights for future implementation of data science algorithms on near-term quantum devices where problem size has been reduced by coreset selection.Quantum computing is anticipated to offer immense computational capabilities which could provide efficient solutions to many data science problems. However, the current generation of quantum devices are small and noisy, which makes it difficult to process large data sets relevant for practical problems. Coreset selection aims to circumvent this problem by reducing the size of input data without compromising the accuracy. Recent work has shown that coreset selection can help to implement quantum K-Means clustering problem. However, the impact of coreset selection on the performance of quantum K-Means clustering has not been explored. In this work, we compare the relative performance of two coreset techniques (BFL16 and ONESHOT), and the size of coreset construction in each case, with respect to a variety of data sets and layout the advantages and limitations of coreset selection in implementing quantum algorithms. We also investigated the effect of depolarisation quantum noise and bit-flip error, and implemented the Quantum AutoEncoder technique for surpassing the noise effect. Our work provides useful insights for future implementation of data science algorithms on near-term quantum devices where problem size has been reduced by coreset selection.

arXiv:2206.07852Jun 16, 20220 citations

From Bits to Qubits: A Benchmarking Analysis of K-Means Algorithm on Classical and Quantum Platforms

Ó, Francisco Loureiro Rosa Ramos do

Classical machine learning algorithms are increasingly challenged by the growing complexity of datasets, motivating the exploration of quantum computing as a potential solution. However, current literature lacks comprehensive empirical analyses directly benchmarking classical algorithms against quantum-assisted counterparts for small but high-dimensional standardized datasets. This research aims to address this gap by comparing the performance of the k-means clustering algorithm on classical and hybrid quantum-classical computing platforms. Using a small dataset, we assess computational speed, clustering accuracy, and scalability. Our findings reveal that while hybrid quantum implementations offer theoretical benefits, in practice they incur significantly higher computational overhead and reduced clustering accuracy due to current technological constraints. These insights highlight the critical need for improved quantum hardware and algorithms, guiding future research directions in quantum-enhanced machine learning.Classical machine learning algorithms are increasingly challenged by the growing complexity of datasets, motivating the exploration of quantum computing as a potential solution. However, current literature lacks comprehensive empirical analyses directly benchmarking classical algorithms against quantum-assisted counterparts for small but high-dimensional standardized datasets. This research aims to address this gap by comparing the performance of the k-means clustering algorithm on classical and hybrid quantum-classical computing platforms. Using a small dataset, we assess computational speed, clustering accuracy, and scalability. Our findings reveal that while hybrid quantum implementations offer theoretical benefits, in practice they incur significantly higher computational overhead and reduced clustering accuracy due to current technological constraints. These insights highlight the critical need for improved quantum hardware and algorithms, guiding future research directions in quantum-enhanced machine learning.

Oct 31, 20250 citations

Near-Optimal Quantum Coreset Construction Algorithms for Clustering

Yecheng Xue, Xiaoyu Chen, Tongyang Li +1 more

$k$ -Clustering in $\mathbb{R}^d$ (e.g., $k$ -median and $k$ -means) is a fundamental machine learning problem. While near-linear time approximation algorithms were known in the classical setting for a dataset with cardinality $n$ , it remains open to find sublinear-time quantum algorithms. We give quantum algorithms that find coresets for $k$ -clustering in $\mathbb{R}^d$ with $\tilde{O}(\sqrt{nk}d^{3/2})$ query complexity. Our coreset reduces the input size from $n$ to $\mathrm{poly}(kε^{-1}d)$ , so that existing $α$ -approximation algorithms for clustering can run on top of it and yield $(1 + ε)α$ -approximation. This eventually yields a quadratic speedup for various $k$ -clustering approximation algorithms. We complement our algorithm with a nearly matching lower bound, that any quantum algorithm must make $Ω(\sqrt{nk})$ queries in order to achieve even $O(1)$ -approximation for $k$ -clustering.$k$-Clustering in $\mathbb{R}^d$ (e.g., $k$-median and $k$-means) is a fundamental machine learning problem. While near-linear time approximation algorithms were known in the classical setting for a dataset with cardinality $n$, it remains open to find sublinear-time quantum algorithms. We give quantum algorithms that find coresets for $k$-clustering in $\mathbb{R}^d$ with $\tilde{O}(\sqrt{nk}d^{3/2})$ query complexity. Our coreset reduces the input size from $n$ to $\mathrm{poly}(kε^{-1}d)$, so that existing $α$-approximation algorithms for clustering can run on top of it and yield $(1 + ε)α$-approximation. This eventually yields a quadratic speedup for various $k$-clustering approximation algorithms. We complement our algorithm with a nearly matching lower bound, that any quantum algorithm must make $Ω(\sqrt{nk})$ queries in order to achieve even $O(1)$-approximation for $k$-clustering.

arXiv:2306.02826Jun 5, 20230 citations

k

-Clustering in

\mathbb{R}^d

(e.g.,

k

-median and

k

-means) is a fundamental machine learning problem. While near-linear time approximation algorithms were known in the classical setting for a dataset with cardinality

n

, it remains open to find sublinear-time quantum algorithms. We give quantum algorithms that find coresets for

k

-clustering in

\mathbb{R}^d

with

\tilde{O}(\sqrt{nk}d^{3/2})

query complexity. Our coreset reduces the input size from

n

\mathrm{poly}(kε^{-1}d)

, so that existing

α

-approximation algorithms for clustering can run on top of it and yield

(1 + ε)α

-approximation. This eventually yields a quadratic speedup for various

k

-clustering approximation algorithms. We complement our algorithm with a nearly matching lower bound, that any quantum algorithm must make

Ω(\sqrt{nk})

queries in order to achieve even

O(1)

-approximation for

k

-clustering.