200 research outputs found
Double entanglement and quantum cryptography
We propose a quantum transmission based on bi-photons which are
doubly-entangled both in polarisation and phase. This scheme finds a natural
application in quantum cryptography, where we show that an eventual
eavesdropper is bound to introduce a larger error on the quantum communication
than for a single entangled bi-photon communication, when steeling the same
information
Can experimental tests of Bell inequalities performed with pseudoscalar mesons be definitive?
We discuss if experimental tests of Bell inequalities performed with
pseudoscalar mesons (K or B) can be definitive. Our conclusion is that this is
not the case, for the efficiency loophole cannot be eliminated.Comment: submitted for publicatio
Experimental test of local realism using non-maximally entangled states
In this paper we describe a test of Bell inequalities using a non- maximally
entangled state, which represents an important step in the direction of
eliminating the detection loophole. The experiment is based on the creation of
a polarisation entangled state via the superposition, by use of an appropriate
optics, of the spontaneous fluorescence emitted by two non-linear crystals
driven by the same pumping laser.Comment: proc. of QCM&C, Capr
A new conception experimental test of Bell inequalities using non-maximally entangled states
We report on a test of Bell inequalities using a non-maximally entangled
state, which represents an important step in the direction of eliminating the
detection loophole. The experiment is based on the creation of a polarisation
entangled state via the superposition, by use of an appropriate optics, of the
spontaneous fluorescence emitted by two non-linear crystals driven by the same
pumping laser. The alignment has profitably taken advantage from the use of an
optical amplifier scheme, where a solid state laser is injected into the
crystals together with the pumping laser. In principle a very high total
quantum efficiency can be reached using this configuration and thus the final
version of this experiment can lead to a resolution of the detection loophole,
we carefully discuss the conditions which must be satisfied for reaching this
result.Comment: to be published in Proc. of International Workshop on Optics and
Spectroscopy (Hanoi, Vietnam
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