Semi-device-independent bounds on entanglement

Yeong-Cherng Liang*, Tamas Vertesi, Nicolas Brunner

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)

45 Citations (Scopus)

Abstract

Detection and quantification of entanglement in quantum resources are two key steps in the implementation of various quantum-information processing tasks. Here, we show that Bell-type inequalities are not only useful in verifying the presence of entanglement but can also be used to bound the entanglement of the underlying physical system. Our main tool consists of a family of Clauser-Horne-like Bell inequalities that cannot be violated maximally by any finite-dimensional maximally entangled state. Using these inequalities, we demonstrate the explicit construction of both lower and upper bounds on the concurrence for two-qubit states. The fact that these bounds arise from Bell-type inequalities also allows them to be obtained in a semi-device-independent manner, that is, with assumption of the dimension of the Hilbert space but without resorting to any knowledge of the actual measurements being performed on the individual subsystems.

Original languageEnglish
Article number022108
Number of pages7
JournalPhysical Review A: Atomic, Molecular and Optical Physics
Volume83
Issue number2
DOIs
Publication statusPublished - 24 Feb 2011

Keywords

  • BELL INEQUALITIES
  • MAXIMAL VIOLATION
  • QUANTUM
  • STATES
  • THEOREM

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