English
Related papers

Related papers: New variants of the Bell-Kochen-Specker theorem

200 papers

The Kochen-Specker theorem proves the inability to assign, simultaneously, noncontextual definite values to all (of a finite set of) quantum mechanical observables in a consistent manner. If one assumes that any definite values behave…

Quantum Physics · Physics 2015-10-06 Alastair A. Abbott , Cristian S. Calude , Karl Svozil

We revisit the computation of correlations of spin projections onto unit vectors for spin-1/2 particles in Quantum Mechanics. We then choose one of the Boole inequalities that, as we recall, must be obeyed by collections of sequences of…

Quantum Physics · Physics 2012-04-12 Edson de Faria , Charles Tresser

System of 1/2 spin particles is observed repeatedly using Stern-Gerlach apparatuses with rotated orientations. Synthesis of such non-commuting observables is analyzed using maximum likelihood estimation as an example of quantum state…

Quantum Physics · Physics 2009-10-31 Z. Hradil , J. Summhammer , G. Badurek , H. Rauch

The non-hermitian states that lead to separation of the four Bell states are examined. In the absence of interactions, a new quantum state of spin magnitude 1/(root(2) is predicted. Properties of these states show that an isolated spin is a…

General Physics · Physics 2009-08-25 B. C. Sanctuary

Experimental tests of Bell-type inequalities distinguishing between quantum mechanics and local realistic theories remain of considerable interest if performed on massive particles, for which no conclusive result has yet been obtained. Only…

Quantum Physics · Physics 2015-04-09 M. Iannuzzi , R. Messi , D. Moricciani , A. Orecchini , F. Sacchetti

Though John Bell had claimed that his spin-1/2 example of a hidden-variable theory(HV) is an \emph{explicit} counterexample to von Neumann's proof of the non-existence of hidden variable theories empirically equivalent to quantum mechanics,…

Quantum Physics · Physics 2016-11-14 Kaushik Borah , N. D. Hari Dass

A nonclassical feature of the fourth-order interference at a beam splitter, that genuine photon spin singlets are emitted in predetermined directions even when incident photons are unpolarized, has been used in a proposal for an experiment…

Quantum Physics · Physics 2009-10-31 Mladen Pavicic

Quantum contextuality is one of the fundamental notions in quantum mechanics. Proofs of the Kochen-Specker theorem and noncontextuality inequalities are two means for revealing the contextuality phenomenon in quantum mechanics. It has been…

Quantum Physics · Physics 2015-09-08 Xiao-Dong Yu , Yan-Qing Guo , D. M. Tong

In a general setting, we introduce a new bipartite state property sufficient for the validity of the perfect correlation form of the original Bell inequality for any three bounded quantum observables. A bipartite quantum state with this…

Quantum Physics · Physics 2007-05-23 Elena R. Loubenets

The violation of a Bell inequality is a striking demonstration of how quantum mechanics contradicts local realism. Although the original argument was presented with a pair of spin 1/2 particles, so far Bell inequalities have been shown to…

Quantum Physics · Physics 2019-10-30 D. K. Shin , B. M. Henson , S. S. Hodgman , T. Wasak , J. Chwedenczuk , A. G. Truscott

A quantum kaleidoscope is defined as a set of observables, or states, consisting of many different subsets that provide closely related proofs of the Bell-Kochen-Specker (BKS) and Bell nonlocality theorems. The kaleidoscopes prove the BKS…

Quantum Physics · Physics 2009-11-11 P. K. Aravind

For two particles with different spin, we derive the Bell's inequality. The inequality is investigated for two systems combining spin-1 and 1/2; spin-1/2 and 3/2. We show that for these states Bell's inequality is violated.

Quantum Physics · Physics 2012-01-10 Shahpoor Moradi

We present a number of observables-based proofs of the Kochen-Specker (KS) theorem based on the N-qubit Pauli group for N >= 4, thus adding to the proofs that have been presented earlier for the two- and three-qubit groups. These proofs…

Quantum Physics · Physics 2013-08-09 Mordecai Waegell , P. K. Aravind

To every binary linear [n,k]-code C we associate a quantum state ("codeket") belonging to the n-th tensor power of the 2-dimensional complex Hilbert space associated to the spin 1/2 particle. We completely characterize the expectation…

Quantum Physics · Physics 2007-05-23 Mihai Caragiu

Contemporary versions of Bell's argument against local hidden variable (LHV) theories are based on the Clauser Horne Shimony and Holt (CHSH) inequality, and various attempts to generalize it. The amount of violation of these inequalities…

Quantum Physics · Physics 2009-11-13 Itamar Pitowsky

In the Greenberger-Horne-Zeilinger-Mermin (GHZM) proof of Bell's theorem, a source periodically emits an entangled state of three particles whose properties are analyzed by three distant observers and used to prove Bell's nonlocality…

Quantum Physics · Physics 2007-05-23 P. K. Aravind

We revisit the Bell--CHSH scenario for two spin-\(\tfrac{1}{2}\) particles and isolate the precise algebraic origin of the Bell contradiction. On the quantum side, spin-\(\tfrac{1}{2}\) is described by a noncommutative spinor (Clifford)…

Quantum Physics · Physics 2025-12-15 G. A. Koroteev

The Kochen-Specker theorem is a basic and fundamental 50 year old non-existence result affecting the foundations of quantum mechanix, strongly implying the lack of any meaningful notion of "quantum realism", and typically leading to…

Quantum Physics · Physics 2019-04-11 Del Rajan , Matt Visser

The one-dimensional Klein-Gordon equation is investigated with the most general Lorentz structure for the external potentials. The analysis and calculation of the reflection and transmission coefficients for the scattering of particles in a…

Quantum Physics · Physics 2008-11-26 Tatiana R. Cardoso , Antonio S. de Castro

The experimental violation of Bell inequality establishes necessary but not sufficient conditions that any theory must obey. Namely, a theory compatible with the experimental observations can satisfy at most two of the three hypotheses at…

Quantum Physics · Physics 2012-10-22 Antonio Di Lorenzo