| 1. |
- Amselem, Elias, et al.
(författare)
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Experimental fully contextual correlations
- 2012
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 108:20, s. 200405-
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Tidskriftsartikel (refereegranskat)abstract
- Quantum correlations are contextual yet, in general, nothing prevents the existence of even more contextual correlations. We identify and test a noncontextuality inequality in which the quantum violation cannot be improved by any hypothetical postquantum theory, and use it to experimentally obtain correlations in which the fraction of noncontextual correlations is less than 0.06. Our correlations are experimentally generated from the results of sequential compatible tests on a four-state quantum system encoded in the polarization and path of a single photon.
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| 2. |
- Cabello, Adan, et al.
(författare)
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Quantum social networks
- 2012
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Ingår i: Journal of Physics A. - : IOP Publishing. - 1751-8113 .- 1751-8121. ; 45:28, s. 285101-
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Tidskriftsartikel (refereegranskat)abstract
- We introduce a physical approach to social networks (SNs) in which each actor is characterized by a yes-no test on a physical system. This allows us to consider SNs beyond those originated by interactions based on pre-existing properties, as in a classical SN (CSN). As an example of SNs beyond CSNs, we introduce quantum SNs (QSNs) in which actor i is characterized by a test of whether or not the system is in a quantum state |psi(i)>. We show that QSNs outperform CSNs for a certain task and some graphs. We identify the simplest of these graphs and show that graphs in which QSNs outperform CSNs are increasingly frequent as the number of vertices increases. We also discuss more general SNs and identify the simplest graphs in which QSNs cannot be outperformed.
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| 3. |
- Kleinmann, Matthias, et al.
(författare)
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Memory cost of quantum contextuality
- 2011
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Ingår i: New Journal of Physics. - : Institute of Physics. - 1367-2630. ; 13:113011
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Tidskriftsartikel (refereegranskat)abstract
- The simulation of quantum effects requires certain classical resources, and quantifying them is an important step to characterize the difference between quantum and classical physics. For a simulation of the phenomenon of state-independent quantum contextuality, we show that the minimum amount of memory used by the simulation is the critical resource. We derive optimal simulation strategies for important cases and prove that reproducing the results of sequential measurements on a two-qubit system requires more memory than the information-carrying capacity of the system.
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