Size-Independent Robustness in Multipartite Bell Self-Testing
Abstract
Practical robust self-testing of multipartite entanglement has so far been restricted to small-scale systems due to error bounds that degrade severely with system size. In this work, we establish multipartite self-testing with robustness independent of the size of the quantum network. We derive a fully analytic, device-independent self-testing bound for n-qubit Greenberger-Horne-Zeilinger (GHZ) states. The bound scales linearly with the observed violation error and lies universally within a constant factor of two from a theoretical upper bound. Furthermore, the operator-inequality framework reduces the verification of the conjectured optimal bound to a highly efficient numerical check, which we perform up to n=100. Consequently, GHZ entanglement can be certified under a fixed noise level in arbitrarily large systems, enabling scalable device-independent verification.
Related
- Experimental certification of multipartite Bell correlations using only few-body symmetric correlations
- Noise robust self testing from genuine local operation shared randomness multipartite nonlocality Tests
- Sharp State-Independent Uncertainty Relations for Multipartite systems
- All Bell inequalities with a quantum advantage in the minimal scenario are self-testing
- Improving device-independent quantum key distribution protocols through multiple routed Bell tests
BibTeX
@misc{cao2026sizeindependent,
title = {{Size-Independent Robustness in Multipartite Bell Self-Testing}},
author = {Shen Cao and Xingjian Zhang and Fei Shi and Qi Zhao},
howpublished = {arXiv},
year = {2026},
month = aug,
doi = {10.48550/arxiv.2608.30851},
eprint = {2608.30851},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.30851},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Size-Independent Robustness in Multipartite Bell Self-Testing
AU - Shen Cao
AU - Xingjian Zhang
AU - Fei Shi
AU - Qi Zhao
PY - 2026
DA - 2026/08/31
PB - arXiv
DO - 10.48550/arxiv.2608.30851
UR - https://arxiv.org/abs/2608.30851
AB - Practical robust self-testing of multipartite entanglement has so far been restricted to small-scale systems due to error bounds that degrade severely with system size. In this work, we establish multipartite self-testing with robustness independent of the size of the quantum network. We derive a fully analytic, device-independent self-testing bound for n-qubit Greenberger-Horne-Zeilinger (GHZ) states. The bound scales linearly with the observed violation error and lies universally within a constant factor of two from a theoretical upper bound. Furthermore, the operator-inequality framework reduces the verification of the conjectured optimal bound to a highly efficient numerical check, which we perform up to n=100. Consequently, GHZ entanglement can be certified under a fixed noise level in arbitrarily large systems, enabling scalable device-independent verification.
ER -