Observation of Four-Photon Orbital Angular Momentum Entanglement

Author(s)
B. C. Hiesmayr, M. J. A. de Dood, W. Loffler
Abstract

We demonstrate genuine multipartite quantum entanglement of four photons in their orbital angular momentum degrees of freedom, where a high-dimensional discrete Hilbert space is attached to each photon. This can encode more quantum information compared to the qubit case, but it is a long-standing problem to entangle more than two such photons. In our experiment we use pulsed spontaneous parametric down-conversion to produce the photon quadruplets, which allows us to detect about one four-photon event per second. By means of quantum state reconstruction and a suitable witness operator we find that the photon quadruplets form a genuine multipartite entangled symmetric Dicke state. This opens a new tool for addressing foundational questions in quantum mechanics, and for exploration of novel high-dimensional multiparty quantum information applications such as secret sharing.

Organisation(s)
Particle Physics, Quantum Optics, Quantum Nanophysics and Quantum Information
External organisation(s)
Leiden University
Journal
Physical Review Letters
Volume
116
No. of pages
5
ISSN
0031-9007
DOI
https://doi.org/10.1103/PhysRevLett.116.073601
Publication date
02-2016
Peer reviewed
Yes
Austrian Fields of Science 2012
103024 Quantum field theory, 103026 Quantum optics, 103034 Particle physics
Keywords
ASJC Scopus subject areas
Physics and Astronomy(all)
Portal url
https://ucris.univie.ac.at/portal/en/publications/observation-of-fourphoton-orbital-angular-momentum-entanglement(2e01712d-bbb3-4090-bb35-359592842c30).html