Experimental verification of multipartite entanglement in quantum networks.
Multipartite entangled states are a fundamental resource for a wide range of quantum information processing tasks. In particular, in quantum networks, it is essential for the parties involved to be able to verify if entanglement is present before they carry out a given distributed task. Here we design and experimentally demonstrate a protocol that allows any party in a network to check if a source is distributing a genuinely multipartite entangled state, even in the presence of untrusted parties. The protocol remains secure against dishonest behaviour of the source and other parties, including the use of system imperfections to their advantage. We demonstrate the verification protocol in a three- and four-party setting using polarization-entangled photons, highlighting its potential for realistic photonic quantum communication and networking applications.
Quantum Engineering Technology Laboratory, Department of Electrical and Electronic Engineering, University of Bristol, Woodland Road, Bristol BS8 1UB, UK.
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W
McCutcheon
School of Informatics, University of Edinburgh, Edinburgh EH89AB, UK.
A
A
Pappa
Quantum Engineering Technology Laboratory, Department of Electrical and Electronic Engineering, University of Bristol, Woodland Road, Bristol BS8 1UB, UK.
B A
BA
Bell
Quantum Engineering Technology Laboratory, Department of Electrical and Electronic Engineering, University of Bristol, Woodland Road, Bristol BS8 1UB, UK.
A
A
McMillan
INRIA, Paris Rocquencourt, SECRET Project Team, Paris 75589, France.
A
A
Chailloux
LTCI, CNRS, Telecom ParisTech, Université Paris-Saclay, 75013 Paris, France.
T
T
Lawson
Department of Physics and Astronomy, Botswana International University of Science and Technology, P/Bag 16, Palapye, Botswana.
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M
Mafu
LTCI, CNRS, Telecom ParisTech, Université Paris-Saclay, 75013 Paris, France.
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D
Markham
LTCI, CNRS, Telecom ParisTech, Université Paris-Saclay, 75013 Paris, France.
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E
Diamanti
CNRS IRIF, Université Paris 7, Paris 75013 France.|Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543, Singapore.
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I
Kerenidis
Quantum Engineering Technology Laboratory, Department of Electrical and Electronic Engineering, University of Bristol, Woodland Road, Bristol BS8 1UB, UK.
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JG
Rarity
School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4001, South Africa.|National Institute for Theoretical Physics, University of KwaZulu-Natal, Durban 4001, South Africa.
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MS
Tame
D000465:Algorithms; D017076:Computer-Aided Design; D001330:Electronic Data Processing / Q000379:methods*; D006801:Humans; D008962:Models, Theoretical; D017785:Photons; D011789:Quantum Theory