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Tomography is Necessary for Universal Entanglement Detection with Single-Copy Observables.
- Source :
-
Physical Review Letters . Jun2016, Vol. 116 Issue 23, p1-1. 1p. - Publication Year :
- 2016
-
Abstract
- Entanglement, one of the central mysteries of quantum mechanics, plays an essential role in numerous tasks of quantum information science. A natural question of both theoretical and experimental importance is whether universal entanglement detection can be accomplished without full state tomography. In this Letter, we prove a no-go theorem that rules out this possibility for nonadaptive schemes that employ single-copy measurements only. We also examine a previously implemented experiment [H. Park et al., Phys. Rev. Lett. 105, 230404 (2010)], which claimed to detect entanglement of two-qubit states via adaptive single-copy measurements without full state tomography. In contrast, our simulation and experiment both support the opposite conclusion that the protocol, indeed, leads to full state tomography, which supplements our no-go theorem. These results reveal a fundamental limit of single-copy measurements in entanglement detection and provide a general framework of the detection of other interesting properties of quantum states, such as the positivity of partial transpose and the k-symmetric extendibility. [ABSTRACT FROM AUTHOR]
- Subjects :
- *QUANTUM entanglement
*QUANTUM information science
*QUANTUM measurement
Subjects
Details
- Language :
- English
- ISSN :
- 00319007
- Volume :
- 116
- Issue :
- 23
- Database :
- Academic Search Index
- Journal :
- Physical Review Letters
- Publication Type :
- Academic Journal
- Accession number :
- 116939160
- Full Text :
- https://doi.org/10.1103/PhysRevLett.116.230501