Entanglement detection with bounded reference frames

Author(s)
Fabio Costa, Nicholas Harrigan, Terry Rudolph, Caslav Brukner
Abstract

Quantum experiments usually assume the existence of perfect, classical reference frames (RFs), which allow for the specification of measurement settings (e.g. orientation of the Stern-Gerlach magnet in spin measurements) with arbitrary precision. If the RFs are 'bounded' (i.e. quantum systems themselves, having a finite number of degrees of freedom), only limited precision can be attained. Using spin coherent states as bounded RFs, we have found the minimum size needed for them to violate local realism for entangled spin systems. For composite systems of spin 1/2 particles, RFs of very small size are sufficient for the violation; however, to see this violation for macroscopic entangled spins, the size of the RF must be at least quadratically larger than that of the spins. The unavailability of such RFs gives a possible explanation for the non-observance of violation of local realism in everyday experience.

Organisation(s)
Quantum Optics, Quantum Nanophysics and Quantum Information
External organisation(s)
Imperial College London
Journal
New Journal of Physics
Volume
11
No. of pages
11
ISSN
1367-2630
DOI
https://doi.org/10.1088/1367-2630/11/12/123007
Publication date
2009
Peer reviewed
Yes
Austrian Fields of Science 2012
103026 Quantum optics
Portal url
https://ucrisportal.univie.ac.at/en/publications/entanglement-detection-with-bounded-reference-frames(9fa685be-b312-4ad2-958f-78c48b36e6d3).html