Beating detection loophole in nonlinear entanglement witnesses
arXiv:1906.09046 · doi:10.1103/PhysRevA.100.062333
Abstract
Detectors in the laboratory are often unlike their ideal theoretical cousins. They have non-ideal efficiencies, which may then lead to non-trivial implications. We show how it is possible to predict correct answers about whether a shared quantum state is entangled in spite of finite detector efficiencies, when the tool for entanglement detection is a nonlinear entanglement witness. We first consider the detection loophole for shared quantum states with nonpositive partial transpose. We subsequently find nonlinear witness operators for bound entangled states with positive partial transpose, and show how the detection loophole can be closed also in such instances.
v2: 7 pages, 2 figures, error fixed from Sec. V
References in corpus (12)
- Entanglement detection
- Tunable ion-photon entanglement in an optical cavity
- Optimal entanglement witnesses based on local orthogonal observables
- Entanglement criteria based on local uncertainty relations are strictly stronger than the computable cross norm criterion
- Determining lower bounds on a measure of multipartite entanglement from few local observables
- Detection Loophole in Bell experiments: How post-selected local correlations can look non-local
- Entanglement witnesses and a loophole problem
- Nonlinear entanglement witnesses, covariance matrices and the geometry of separable states
- Iterations of nonlinear entanglement witnesses
- Detecting three-qubit bound MUB diagonal entangled states via Nonlinear optimal entanglement witnesses
- The separability versus entanglement problem
- A hierarchy of entanglement criteria for four qubit symmetric Greenberger-Horne-Zeilinger diagonal states
Cited by in corpus (7)
- Sequential measurement-device-independent entanglement detection by multiple observers
- Efficient nonlinear witnessing of non-absolutely separable states with lossy detectors
- Detection loophole in measurement-device-independent entanglement witness
- Noisy quantum input loophole in measurement-device-independent entanglement witnesses
- Measurement-device-independent nonlinear entanglement witnesses
- Effects of the detection loophole on rival entanglement attestation techniques
- Closing loopholes of measurement-device-independent nonlinear entanglement witnesses