Nonlocal generalized quantum measurements of bipartite spin products without maximal entanglement

P. Vidil, K. Edamatsu

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


Measuring a nonlocal observable on a space-like separated quantum system is a resource-hungry and experimentally challenging task. Several theoretical measurement schemes have already been proposed to increase its feasibility, using a shared maximally-entangled ancilla. We present a new approach to this problem, using the language of generalized quantum measurements, to show that it is actually possible to measure a nonlocal spin product observable without necessarily requiring a maximally-entangled ancilla. This approach opens the door to more economical arbitrary-strength nonlocal measurements, with applications ranging from nonlocal weak values to possible new tests of Bell inequalities. The relation between measurement strength and the amount of ancillary entanglement needed is made explicit, bringing a new perspective on the links that tie quantum nonlocality, entanglement and information transmission together.

Original languageEnglish
Article number043004
JournalNew Journal of Physics
Issue number4
Publication statusPublished - 2021 Apr


  • generalized quantum measurements
  • quantum entanglement
  • quantum measurements

ASJC Scopus subject areas

  • Physics and Astronomy(all)


Dive into the research topics of 'Nonlocal generalized quantum measurements of bipartite spin products without maximal entanglement'. Together they form a unique fingerprint.

Cite this