Closing the detection loophole in Bell experiments using qudits.

@article{Vrtesi2010ClosingTD,
  title={Closing the detection loophole in Bell experiments using qudits.},
  author={Tam{\'a}s V{\'e}rtesi and Stefano Pironio and Nicolas Brunner},
  journal={Physical review letters},
  year={2010},
  volume={104 6},
  pages={
          060401
        }
}
We show that the detection efficiencies required for closing the detection loophole in Bell tests can be significantly lowered using quantum systems of dimension larger than two. We introduce a series of asymmetric Bell tests for which an efficiency arbitrarily close to 1/N can be tolerated using N-dimensional systems, and a symmetric Bell test for which the efficiency can be lowered down to 61.8% using four-dimensional systems. Experimental perspectives for our schemes look promising… 

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References

SHOWING 1-10 OF 54 REFERENCES
Detection loophole in asymmetric bell experiments.
The problem of closing the detection loophole with asymmetric systems, such as entangled atom-photon pairs, is addressed. We show that, for the Bell inequality I3322, a minimal detection efficiency
Minimum detection efficiency for a loophole-free atom-photon bell experiment.
TLDR
It is shown that, assuming perfect detection efficiency of the atom, it is possible to perform a loophole-free atom-photon Bell experiment whenever the photodetection efficiency exceeds 0.50.
Proposal for a loophole-free Bell test using homodyne detection.
TLDR
A detailed feasibility analysis suggests that the proposed optical setup allowing for a loophole-free Bell test with efficient homodyne detection opens a promising avenue towards a complete experimental Bell test.
Nonlocality, closing the detection loophole, and communication complexity
It is shown that the detection loophole that arises when trying to rule out local realistic theories as alternatives for quantum mechanics can be closed if the detection efficiency η≥Cd 3 / 4 2 - 0 .
Bell-Type Test of Energy-Time Entangled Qutrits
We have performed a Bell-type test for energy-time entangled qutrits. A method of inferring the Bell violation in terms of an associated interference visibility is derived. Using this scheme we
Robust long-distance entanglement and a loophole-free bell test with ions and photons.
TLDR
The use of two-photon interference allows entanglement distribution free of interferometric sensitivity to the path length of the photons, and opens up the possibility of a loophole-free test of Bell's inequalities.
Complete and deterministic discrimination of polarization Bell states assisted by momentum entanglement
A complete and deterministic Bell state measurement was realized by a simple linear optics experimental scheme which adopts two-photon polarization-momentum hyperentanglement. The scheme, which is
Towards a Loophole-Free Test of Bell's Inequality with Entangled Pairs of Neutral Atoms
Experimental tests of Bell’s inequality allow to distinguish quantum mechanics from local hidden variable theories. Such tests are performed by measuring correlations of two entangled particles
Generation of hyperentangled photon pairs.
TLDR
It is experimentally demonstrate the first quantum system entangled in every degree of freedom (hyperentangled) and reports the tomography of a 2 x 2 x 3 x 3 system (36-dimensional Hilbert space), which is believed to be the first reported photonic entangled system of this size to be so characterized.
Bell inequality violation with two remote atomic qubits.
We observe violation of a Bell inequality between the quantum states of two remote Yb+ ions separated by a distance of about 1 m with the detection loophole closed. The heralded entanglement of two
...
...