Bell nonlocality in quantum networks with unreliable sources: Loophole-free postelection via self-testing
arXiv:2501.14027 · doi:10.1103/bqwm-ll5y
Abstract
We discuss Bell nonlocality in quantum networks with unreliable sources. Our main result is a condition on the observed data which ensures that inconclusive events can be safely discarded, without introducing any loophole. More formally, we characterize the fair-sampling property for measurements in a network. When all measurements are fair-sampling, we show that the post-selection of conclusive outcomes does not compromise the assumption of source independence, hence avoiding the detection loophole. Furthermore, we show that in some cases, the fair-sampling property can in fact be guaranteed based only on observed data. To show this, we prove that saturation of the Finner inequality provides a self-test of the underlying quantum model. We illustrate the relevance of our results by demonstrating an improvement in device-independent randomness generation for a photonic Bell test with a probabilistic source and for the triangle network.
References in corpus (13)
- Device-independent security of quantum cryptography against collective attacks
- Hacking commercial quantum cryptography systems by tailored bright illumination
- Device-independent quantum key distribution secure against collective attacks
- Beyond Bell's Theorem: Correlation Scenarios
- Information-Theoretic Implications of Quantum Causal Structures
- Noisy pre-processing facilitating a photonic realisation of device-independent quantum key distribution
- Partial self-testing and randomness certification in the triangle network
- Towards a minimal example of quantum nonlocality without inputs
- Network Nonlocality via Rigidity of Token-Counting and Color-Matching
- Comparing different approaches for generating random numbers device-independently using a photon pair source
- Topologically Robust Quantum Network Nonlocality
- Noise-robust proofs of quantum network nonlocality
- Closing the detection loophole in the triangle network with high-dimensional photonic states