Data-driven criteria for quantum correlations

Fuente: arXiv
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Auteurs principaux: Krawczyk, Mateusz, Pawłowski, Jarosław, Maśka, Maciej M., Roszak, Katarzyna
Format: Preprint
Publié: 2023
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author Krawczyk, Mateusz
Pawłowski, Jarosław
Maśka, Maciej M.
Roszak, Katarzyna
author_facet Krawczyk, Mateusz
Pawłowski, Jarosław
Maśka, Maciej M.
Roszak, Katarzyna
contents We build a machine learning model to detect correlations in a three-qubit system using a neural network trained in an unsupervised manner on randomly generated states. The network is forced to recognize separable states, and correlated states are detected as anomalies. Quite surprisingly, we find that the proposed detector performs much better at distinguishing a weaker form of quantum correlations, namely, the quantum discord, than entanglement. In fact, it has a tendency to grossly overestimate the set of entangled states even at the optimal threshold for entanglement detection, while it underestimates the set of discordant states to a much lesser extent. In order to illustrate the nature of states classified as quantum-correlated, we construct a diagram containing various types of states -- entangled, as well as separable, both discordant and non-discordant. We find that the near-zero value of the recognition loss reproduces the shape of the non-discordant separable states with high accuracy, especially considering the non-trivial shape of this set on the diagram. The network architecture is designed carefully: it preserves separability, and its output is equivariant with respect to qubit permutations. We show that the choice of architecture is important to get the highest detection accuracy, much better than for a baseline model that just utilizes a partial trace operation.
format Preprint
id arxiv_https___arxiv_org_abs_2307_11091
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Data-driven criteria for quantum correlations
Krawczyk, Mateusz
Pawłowski, Jarosław
Maśka, Maciej M.
Roszak, Katarzyna
Quantum Physics
Machine Learning
We build a machine learning model to detect correlations in a three-qubit system using a neural network trained in an unsupervised manner on randomly generated states. The network is forced to recognize separable states, and correlated states are detected as anomalies. Quite surprisingly, we find that the proposed detector performs much better at distinguishing a weaker form of quantum correlations, namely, the quantum discord, than entanglement. In fact, it has a tendency to grossly overestimate the set of entangled states even at the optimal threshold for entanglement detection, while it underestimates the set of discordant states to a much lesser extent. In order to illustrate the nature of states classified as quantum-correlated, we construct a diagram containing various types of states -- entangled, as well as separable, both discordant and non-discordant. We find that the near-zero value of the recognition loss reproduces the shape of the non-discordant separable states with high accuracy, especially considering the non-trivial shape of this set on the diagram. The network architecture is designed carefully: it preserves separability, and its output is equivariant with respect to qubit permutations. We show that the choice of architecture is important to get the highest detection accuracy, much better than for a baseline model that just utilizes a partial trace operation.
title Data-driven criteria for quantum correlations
topic Quantum Physics
Machine Learning
url https://arxiv.org/abs/2307.11091