| 1. |
- Badziag, Piotr, et al.
(författare)
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Pentagrams and Paradoxes
- 2011
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Ingår i: FOUNDATIONS OF PHYSICS. - : Springer Science Business Media. - 0015-9018 .- 1572-9516. ; 41:3, s. 414-423
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Tidskriftsartikel (refereegranskat)abstract
- Klyachko and coworkers consider an orthogonality graph in the form of a pentagram, and in this way derive a Kochen-Specker inequality for spin 1 systems. In some low-dimensional situations Hilbert spaces are naturally organised, by a magical choice of basis, into SO(N) orbits. Combining these ideas some very elegant results emerge. We give a careful discussion of the pentagram operator, and then show how the pentagram underlies a number of other quantum "paradoxes", such as that of Hardy.
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| 2. |
- Bengtsson, Ingemar, et al.
(författare)
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Pentagrams and paradoxes
- 2011
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Ingår i: Foundations of Physics. ; 41, s. 414-
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Cabello, Adan, et al.
(författare)
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Hybrid ququart-encoded quantum cryptography protected by Kochen-Specker contextuality
- 2011
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Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 84:3, s. 030302-
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Tidskriftsartikel (refereegranskat)abstract
- Quantum cryptographic protocols based on complementarity are not secure against attacks in which complementarity is imitated with classical resources. The Kochen-Specker (KS) theorem provides protection against these attacks, without requiring entanglement or spatially separated composite systems. We analyze the maximum tolerated noise to guarantee the security of a KS-protected cryptographic scheme against these attacks and describe a photonic realization of this scheme using hybrid ququarts defined by the polarization and orbital angular momentum of single photons.
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| 4. |
- Cabello, Adán
(författare)
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Quantum physics : Correlations without parts
- 2011
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 474:7352, s. 456-458
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Tidskriftsartikel (refereegranskat)
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| 5. |
- 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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