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arXiv · 2211.13750

Comparing Singlet Testing Schemes

George Cowperthwaite·Adrian Kent
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Abstract

We compare schemes for testing whether two parties share a two-qubit singlet state. The first, standard, scheme tests Braunstein-Caves (or CHSH) inequalities, comparing the correlations of local measurements drawn from a fixed finite set against the quantum predictions for a singlet. The second, alternative, scheme tests the correlations of local measurements, drawn randomly from the set of those that are $\theta$-separated on the Bloch sphere, against the quantum predictions. We formulate each scheme as a hypothesis test and then evaluate the test power in a number of adversarial scenarios involving an eavesdropper altering or replacing the singlet qubits. We find the `random measurement' test to be superior in most natural scenarios.

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George Cowperthwaite, Adrian Kent. 2022-11-24. Comparing Singlet Testing Schemes. https://doi.org/10.3390/e27050515

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