Minimum detection efficiencies for a loophole-free observable-asymmetric Bell-type test

Journal Article · Mon Mar 15 04:00:00 EDT 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.81.032106· OSTI ID:21408365

Garbarino, G ^[1]

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1. Dipartimento di Fisica Teorica, Universita di Torino and INFN, Sezione di Torino, I-10125 Torino (Italy)

We discuss the problem of finding the most favorable conditions for closing the detection loophole in a test of local realism with a Bell inequality. For a generic nonmaximally entangled two-qubit state and two incompatible bases to be adopted for alternative measurements of two observables a and b on each party, we apply Hardy's proof of nonlocality without inequality and derive an Eberhard-like inequality. For an infinity of nonmaximally entangled states we find that it is possible to refute local realism by requiring perfect detection efficiency for only one of the two observables, say b, to be measured on each party: The test is free from the detection loophole for any value of the detection efficiency corresponding to the other observable a. The maximum tolerable noise in such a loophole-free observable-asymmetric test is also evaluated.

• OSTI ID: 21408365
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 3 Vol. 81; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ASYMMETRY
BELL THEOREM
DETECTION
EFFICIENCY
NOISE
QUANTUM ENTANGLEMENT