Quantum entanglement from random measurements

Autor(en)

Minh Cong Tran, Borivoje Dakic, Francois Arnault, Wieslaw Laskowski, Tomasz Paterek

Abstrakt

We show that the expectation value of squared correlations measured along random local directions is an identifier of quantum entanglement in pure states, which can be directly experimentally assessed if two copies of the state are available. Entanglement can therefore be detected by parties who do not share a common reference frame and whose local reference frames, such as polarizers or Stern-Gerlach magnets, remain unknown. Furthermore, we also show that in every experimental run, access to only one qubit from the macroscopic reference is sufficient to identify entanglement, violate a Bell inequality, and, in fact, observe all phenomena observable with macroscopic references. Finally, we provide a state-independent entanglement witness solely in terms of random correlations and emphasize how data gathered for a single random measurement setting per party reliably detects entanglement. This is only possible due to utilized randomness and should find practical applications in experimental confirmation of multiphoton entanglement or space experiments.

Organisation(en)

Quantenoptik, Quantennanophysik und Quanteninformation

Externe Organisation(en)

Nanyang Technological University (NTU), Österreichische Akademie der Wissenschaften (ÖAW), Université de Limoges, University of Gdańsk, National University of Singapore (NUS)

Journal

Physical Review A

Band

92

Anzahl der Seiten

7

ISSN

1050-2947

DOI

https://doi.org/10.1103/PhysRevA.92.050301

Publikationsdatum

11-2015

Peer-reviewed

Ja

ÖFOS 2012

103036 Theoretische Physik, 103026 Quantenoptik

Schlagwörter

ASJC Scopus Sachgebiete

Atomic and Molecular Physics, and Optics

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/5342bfaa-63de-4921-9a5d-7d8fe5a979c6