BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Quantum Non-Locality in Networks - Nicolas Gisin\, Group of Applie
 d Physics\, University of Geneva\, Switzerland
DTSTART:20231019T131500Z
DTEND:20231019T141500Z
UID:TALK196009@talks.cam.ac.uk
CONTACT:Damian Pitalua-Garcia
DESCRIPTION:Quantum non-locality\, i.e. the violation of some Bell inequal
 ity\, has proven to be an extremely useful concept in analyzing entangleme
 nt\, quantum randomness and cryptography\, among others. In particular\, i
 t led to the fascinating field of device-independent quantum information p
 rocessing.\n\nHistorically\, the idea was that the particles emitted by va
 rious quantum sources carry additional variables\, known as local hidden v
 ariables. The more modern view\, strongly influenced by computer science\,
  refers to these additional variables as shared randomness. This\, however
 \, leads to ambiguity when there is more than one source\, as in quantum n
 etworks. Should the randomness produced by each source be considered as fu
 lly correlated\, as in most common analyses\, or should one analyze the si
 tuation assuming that each source produces independent randomness\, closer
  to the historical spirit?\n\nThe latter is known\, for the case of n inde
 pendent sources\, as n-locality. For example\, in entanglement swapping th
 ere are two sources\, hence “quantumness” should be analyzed using 2-l
 ocality (or\, equivalently\, bi-locality). The situation when the network 
 has loops is especially interesting. Recent results for triangular network
 s will be presented. Another result is that some quantum networks can’t 
 be described by real-number Hilbert spaces.
LOCATION:MR2
END:VEVENT
END:VCALENDAR