Ultrafine Entanglement Witnessing

Abstract

Entanglement witnesses are invaluable for efficient quantum entanglement certification without the need for expensive quantum state tomography. Yet, standard entanglement witnessing requires multiple measurements and its bounds can be elusive as a result of experimental imperfections. Here we introduce and demonstrate a novel procedure for entanglement detection which seamlessly and easily improves any standard witnessing procedure by using additional available information to tighten the witnessing bounds. Moreover, by relaxing the requirements on the witness operators, our method removes the general need for the difficult task of witness decomposition into local observables. We experimentally demonstrate entanglement detection with our approach using a separable test operator and a simple fixed measurement-device for each agent. Finally we show that the method can be generalized to higher-dimensional and multipartite cases with a complexity that scales linearly with the number of parties.

arXiv comment5 pages + 3 pages supplemental material, 4 figures

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Cited by in corpus (22)

• Entanglement in macroscopic systems
• Design and Experimental Performance of Local Entanglement Witness Operators
• Quantitative Coherence Witness for Finite Dimensional States
• Efficient and robust certification of genuine multipartite entanglement in noisy quantum error correction circuits
• Numerical construction of multipartite entanglement witnesses
• Precise detection of multipartite entanglement in four-qubit Greenberger--Horne--Zeilinger diagonal states
• Entanglement verification of noisy N00N states
• A class of Bell diagonal entanglement witnesses in ${\mathbb{C}}^4\otimes {\mathbb{C}}^4$: optimization and the spanning property
• Separable and Inseparable Quantum Trajectories
• Verifying bound entanglement of dephased Werner states
• Optimization of ultrafine entanglement witnesses
• The hierarchies of "witnesses" and the properties and characterization of entangled states as super entanglement witnesses
• Entangled states in the role of witnesses
• Separability Lindblad equation for dynamical open-system entanglement
• Displaced photon-number entanglement tests
• Witness based nonlinear detection of quantum entanglement
• The structure of ultrafine entanglement witnesses
• Joint separable numerical range and bipartite entanglement witness
• A hierarchy of entanglement criteria for four qubit symmetric Greenberger-Horne-Zeilinger diagonal states
• Confident entanglement detection via separable numerical range
• Robust certification of non-projective measurements: theory and experiment
• The entangling power of non-entangling channels