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arXiv · 2607.04035

Robust self-test of the maximally entangled state of two-qubits without assuming unitary observables

Alexandre C. Orthey Jr.·Magdalena Stobińska-Moretto
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Abstract

Standard device-independent self-testing uses Naimark dilation to assume projective measurements, masking the operational limitations of realistic non-unitary observables. We establish a robust pure self-test for the singlet and Pauli observables that entirely circumvents dilation of the measurement apparatus. Assuming a pure state to model an untrusted source, we regularize the physical non-projective operators and derive an analytic $\mathcal{O}(\sqrt{\epsilon})$ robustness bound. Our results suggest that device-independent certification of real implementations is significantly more demanding than standard projective models imply.

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Alexandre C. Orthey Jr., Magdalena Stobińska-Moretto. 2026-07-04. Robust self-test of the maximally entangled state of two-qubits without assuming unitary observables. https://arxiv.org/abs/2607.04035

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