Construction of optimal witness for unknown two-qubit entanglement
arXiv:1006.1491 · doi:10.1103/PhysRevLett.105.230404
Abstract
Whether entanglement in a state can be detected, distilled, and quantified without full state reconstruction is a fundamental open problem. We demonstrate a new scheme encompassing these three tasks for arbitrary two-qubit entanglement, by constructing the optimal entanglement witness for polarization-entangled mixed-state photon pairs without full state reconstruction. With better efficiency than quantum state tomography, the entanglement is maximally distilled by newly developed tunable polarization filters, and quantified by the expectation value of the witness, which equals the concurrence. This scheme is extendible to multiqubit Greenberger-Horne-Zeilinger entanglement.
Phys. Rev. Lett. 105, 230404 (2010); supplementary information (OWitness_sup.pdf) is included in source zip file
References in corpus (4)
Cited by in corpus (11)
- Macroscopic Quantum Entanglement of a Kondo Cloud at Finite Temperature
- Method for universal detection of two-photon polarization entanglement
- Quantifying entanglement of a two-qubit system via measurable and invariant moments of its partially transposed density matrix
- Minimax optimization of entanglement witness operator for the quantification of three-qubit mixed-state entanglement
- Direct method for measuring and witnessing quantum entanglement of arbitrary two-qubit states through Hong-Ou-Mandel interference
- Geometric representation of two-qubit entanglement witnesses
- Exploring classical correlations in noise to recover quantum information using local filtering
- Quantifying mixed-state quantum entanglement by optimal entanglement witness
- Entanglement quantification from collective measurements processed by machine learning
- Dynamic learning of pairwise and three-way entanglement
- Resource-efficient quantum correlation measurements via multicopy neural network methods