Network steering with arbitrarily low detection efficiency of any entangled measurement
Abstract
Quantum nonlocality and its asymmetric counterpart, quantum steering, are among the most intriguing manifestations of quantum mechanics. From a theoretical perspective, they are not only of fundamental significance but also hold promise for a wide range of applications. However, the stringent technological requirements for their experimental observation in a loophole-free way have largely restricted their realization to foundational demonstrations. A major challenge in these setups is the limited detection efficiency of current detectors as to observe nonlocality or steering in the standard scenarios, one requires detectors above a certain critical efficiency which can only be achieved with superconducting detectors. Considering the simplest quantum network, we demonstrate here that quantum steering between two parties, can be demonstrated for any non-zero detection efficiency, if the sources in the network generate states above a critical visibility well-within the current practical limits. This form of quantum steering in networks, is termed swap-steering. Moreover, when the sources are perfect, swap-steering can be observed using any entangled measurement on the untrusted side, even with arbitrarily low detection efficiency. Consequently, two major loopholes, the detection-loophole as well as free-will loophole can be closed easily in quantum steering experiments, when implemented using networks.
Related
- Quantum steering in networks: Measurement-device-independent detection, continuous variables, and practical Gaussian schemes
- One pure steered state implies Einstein-Podolsky-Rosen steering for two-qubit entangled states
- The collapse time of weak measurement on N entangled sites
- Semi-Device-Independent Certification of multi-qubit Entangled Basis Measurement
- Entangled Measurement Outcomes for Optimal Postselection in Quantum Batteries
BibTeX
@misc{sarkar2026network,
title = {{Network steering with arbitrarily low detection efficiency of any entangled measurement}},
author = {Shubhayan Sarkar},
howpublished = {arXiv},
year = {2026},
month = aug,
doi = {10.48550/arxiv.2608.27582},
eprint = {2608.27582},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.27582},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Network steering with arbitrarily low detection efficiency of any entangled measurement
AU - Shubhayan Sarkar
PY - 2026
DA - 2026/08/27
PB - arXiv
DO - 10.48550/arxiv.2608.27582
UR - https://arxiv.org/abs/2608.27582
AB - Quantum nonlocality and its asymmetric counterpart, quantum steering, are among the most intriguing manifestations of quantum mechanics. From a theoretical perspective, they are not only of fundamental significance but also hold promise for a wide range of applications. However, the stringent technological requirements for their experimental observation in a loophole-free way have largely restricted their realization to foundational demonstrations. A major challenge in these setups is the limited detection efficiency of current detectors as to observe nonlocality or steering in the standard scenarios, one requires detectors above a certain critical efficiency which can only be achieved with superconducting detectors. Considering the simplest quantum network, we demonstrate here that quantum steering between two parties, can be demonstrated for any non-zero detection efficiency, if the sources in the network generate states above a critical visibility well-within the current practical limits. This form of quantum steering in networks, is termed swap-steering. Moreover, when the sources are perfect, swap-steering can be observed using any entangled measurement on the untrusted side, even with arbitrarily low detection efficiency. Consequently, two major loopholes, the detection-loophole as well as free-will loophole can be closed easily in quantum steering experiments, when implemented using networks.
ER -