Genuine multipartite entanglement detection with imperfect measurements: concept and experiment

Abstract

Standard procedures for entanglement detection assume that experimenters can exactly implement specific quantum measurements. Here, we depart from such idealizations and investigate, in both theory and experiment, the detection of genuine multipartite entanglement when measurements are subject to small imperfections. For arbitrary qubits number $n$, we construct multipartite entanglement witnesses where the detrimental influence of the imperfection is independent of $n$. In a tabletop four-partite photonic experiment we demonstrate first how a small amount of alignment error can undermine the conclusions drawn from standard entanglement witnesses, and then perform the correction analysis. Furthermore, since we consider quantum devices that are trusted but not perfectly controlled, we showcase advantages in terms of noise resilience as compared to device-independent models.

6+9 pages, 3+7 figures

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Cited by in corpus (10)

• Imprecision plateaus in quantum steering
• Designing three-way entangled and nonlocal two-way entangled single particle states via alternate quantum walks
• Detecting genuine multipartite entanglement using moments of positive maps
• Binarisation of multi-outcome measurements in high-dimensional quantum correlation experiments
• Protecting entanglement witnesses with randomized measurements
• Threetangle in the XY-model class with a non-integrable field background
• Multipartite steering verification with imprecise measurements
• Partitewise Entanglement
• Ability of entanglement and purity to help to detect systematic experimental errors
• Imprecise quantum steering inequalities in tripartite systems