Entanglement witnesses and a loophole problem
arXiv:quant-ph/0608058 · doi:10.1103/PhysRevA.76.012312
Abstract
We consider a possible detector-efficiency loophole in experiments that detect entanglement via the local measurement of witness operators. Here, only local properties of the detectors are known. We derive a general threshold for the detector efficiencies which guarantees that a negative expectation value of a witness is due to entanglement, rather than to erroneous detectors. This threshold depends on the local decomposition of the witness and its measured expectation value. For two-qubit witnesses we find the local operator decomposition that is optimal with respect to closing the loophole.
5 pages, 2 figures, published version
References in corpus (9)
- Separability of Mixed States: Necessary and Sufficient Conditions
- Violation of Bell's inequality under strict Einstein locality conditions
- Scalable multi-particle entanglement of trapped ions
- Optimization of entanglement witnesses
- Witnessing multipartite entanglement
- Detection of entanglement with few local measurements
- Experimental Detection of Entanglement with Polarized Photons
- Reflections upon separability and distillability
- Relations between Entanglement Witnesses and Bell Inequalities
Cited by in corpus (18)
- Entanglement detection
- The Einstein-Podolsky-Rosen paradox: from concepts to applications
- Experimentally faking the violation of Bell's inequalities
- Measurement-Device-Independent Entanglement Witnesses for All Entangled Quantum States
- Resource-efficient measurement device independent entanglement witness
- Spin entanglement, decoherence and Bohm's EPR paradox
- Sequential measurement-device-independent entanglement detection by multiple observers
- Measurement-device-independent quantification of entanglement for given Hilbert space dimension
- Efficient nonlinear witnessing of non-absolutely separable states with lossy detectors
- Characterizing entanglement with geometric entanglement witnesses
- Witnessing Entanglement in Experiments with Correlated Noise
- Beating detection loophole in nonlinear entanglement witnesses
- Detection loophole in measurement-device-independent entanglement witness
- Noisy quantum input loophole in measurement-device-independent entanglement witnesses
- Measurement-device-independent nonlinear entanglement witnesses
- Closing loopholes of measurement-device-independent nonlinear entanglement witnesses
- Entanglement witnessing with untrusted detectors
- Effects of the detection loophole on rival entanglement attestation techniques