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Multiple Observers Can Share the Nonlocality of Half of an Entangled Pair by Using Optimal Weak Measurements

Research output: Contribution to journalArticle

Original languageEnglish
Article number250401
Number of pages4
JournalPhysical Review Letters
Issue number25
Early online date22 Jun 2015
DateAccepted/In press - 3 Dec 2014
DateE-pub ahead of print - 22 Jun 2015
DatePublished (current) - 26 Jun 2015


We investigate the trade-off between information gain and disturbance for von Neumann measurements on spin-1/2 particles, and derive the measurement pointer state that saturates this trade-off, which turns out to be highly unusual. We apply this result to the question of whether the nonlocality of a single particle from an entangled pair can be shared among multiple observers that act sequentially and independently of each other, and show that an arbitrarily long sequence of such observers can all violate the Clauser-Horne-Shimony-Holt-Bell inequality.

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    Rights statement: This is the author accepted manuscript (AAM). The final published version (version of record) is available online via American Physical Society at

    Accepted author manuscript, 1 MB, PDF document


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