Complementarity reveals bound entanglement of two twisted photons

Author(s)
Beatrix C. Hiesmayr, Wolfgang Löffler
Abstract

We demonstrate the detection of bipartite bound entanglement as predicted by the Horodecki's in 1998. Bound entangled states, being heavily mixed entangled quantum states, can be produced by incoherent addition of pure entangled states. Until 1998 it was thought that such mixing could always be reversed by entanglement distillation; however, this turned out to be impossible for bound entangled states. The purest form of bound entanglement is that of only two particles, which requires higher-dimensional (d > 2) quantum systems. We realize this using photon qutrit (d = 3) pairs produced by spontaneous parametric downconversion, that are entangled in the orbital angular momentum degrees of freedom, which is scalable to high dimensions. Entanglement of the photons is confirmed via a 'maximum complementarity protocol'. This conceptually simple protocol requires only maximized complementary of measurement bases; we show that it can also detect bound entanglement. We explore the bipartite qutrit space and find that, also experimentally, a significant portion of the entangled states are actually bound entangled.

Organisation(s)
Particle Physics
External organisation(s)
Leiden University
Journal
New Journal of Physics
Volume
15
No. of pages
15
ISSN
1367-2630
DOI
https://doi.org/10.1088/1367-2630/15/8/083036
Publication date
08-2013
Peer reviewed
Yes
Austrian Fields of Science 2012
103036 Theoretical physics, 103009 Solid state physics, 103025 Quantum mechanics
Keywords
Portal url
https://ucrisportal.univie.ac.at/en/publications/complementarity-reveals-bound-entanglement-of-two-twisted-photons(abcb2655-91ca-4f52-9682-2fc4d25d0210).html