PreprintCC BY 4.0arXiv
Robust self-test of the maximally entangled state of two-qubits without assuming unitary observables
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 𝒪(√ε) 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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BibTeX
@misc{jr2026robust,
title = {{Robust self-test of the maximally entangled state of two-qubits without assuming unitary observables}},
author = {Alexandre C. Orthey Jr. and Magdalena Stobińska-Moretto},
howpublished = {arXiv},
year = {2026},
month = aug,
doi = {10.48550/arxiv.2607.04035},
eprint = {2607.04035},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2607.04035},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Robust self-test of the maximally entangled state of two-qubits without assuming unitary observables
AU - Alexandre C. Orthey Jr.
AU - Magdalena Stobińska-Moretto
PY - 2026
DA - 2026/08/31
PB - arXiv
DO - 10.48550/arxiv.2607.04035
UR - https://arxiv.org/abs/2607.04035
AB - 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 𝒪(√ε) robustness bound. Our results suggest that device-independent certification of real implementations is significantly more demanding than standard projective models imply.
ER -