Speakable and Unspeakable in Quantum Mechanics

Bell, J. S.; Aspect, Alain

doi:10.1017/cbo9780511815676

Cited by 2,080 publications

(3,383 citation statements)

References 0 publications

Supporting

Mentioning

3,199

Contrasting

Unclassified

Order By: Relevance

“…This inequality bears great resemblance to a CHSH Bell inequality [7,8]. In the context of Bell inequalities, it has been shown that the existence of "hidden variables" reproducing the correct probability distributions is equivalent to the condition that joint probabilities exist for all triples [9].…”

Section: Let Us Denote the Measurement Results Bymentioning

confidence: 93%

Joint measurements of spin, operational locality, and uncertainty

2005

Self Cite

View full text Add to dashboard Cite

Joint, or simultaneous, measurements of non-commuting observables are possible within quantum mechanics, if one accepts an increase in the variances of the jointly measured observables. In this paper, we discuss joint measurements of a spin 1/2 particle along any two directions. Starting from an operational locality principle, it is shown how to obtain a bound on how sharp the joint measurement can be. We give a direct interpretation of this bound in terms of an uncertainty relation.

show abstract

Section: Let Us Denote the Measurement Results Bymentioning

confidence: 93%

Joint measurements of spin, operational locality, and uncertainty

2005

Self Cite

View full text Add to dashboard Cite

show abstract

“…Consider now the joint probability for outcomes A = +1, B = +1 whenâ =b =n 1 . In a Bell Local theory, this joint probability must factor into a product as follows:…”

Section: Hidden Variablesmentioning

confidence: 99%

“…Bell's Theorem [1] has given rise to a unique situation in science. Despite being hailed from all quarters as fundamentally important ("the most profound discovery of science," says H. P. Stapp [2]), the meaning of the theorem -what, exactly, it proves -remains widely and hotly contested.…”

Section: Introductionmentioning

confidence: 99%

“…In the first camp are those who believe that Bell's Theorem proves that non-locality is a fact of nature, which must be reflected in any adequate theory. [1,3,4,5,6] Then there are, in the second camp, those who believe that Bell's Theorem proves only the impossibility of empirically viable local "hidden variable" alternatives to orthodox quantum theory. [7,8] It is widely accepted (by people in both camps) that two assumptions -locality and hidden variables -are needed in the derivation of the Bell Inequalities.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Bell Locality and the Nonlocal Character of Nature

Norsen

2006

Found Phys Lett

View full text Add to dashboard Cite

It is demonstrated that hidden variables of a certain type follow logically from a certain local causality requirement (``Bell Locality'') and the empirically well-supported predictions of quantum theory for the standard EPR-Bell setup. The demonstrated hidden variables are precisely those needed for the derivation of the Bell Inequalities. We thus refute the widespread view that empirical violations of Bell Inequalities leave open a choice of whether to reject (i) locality or (ii) hidden variables. Both principles are indeed assumed in the derivation of the inequalities, but since, as we demonstrate here, (ii) actually follows from (i), there is no choice but to blame the violation of Bell's Inequality on (i). Our main conclusion is thus that no Bell Local theory can be consistent with what is known from experiment about the correlations exhibited by separated particles. Aside from our conclusion being based on a different sense of locality this conclusion resembles one that has been advocated recently by H.P. Stapp. We therefore also carefully contrast the argument presented here to that proposed by Stapp.Comment: To appear in Foundations of Physics Letters; 11 pages, 2 figure

show abstract

“…In terms of quantum-mechanical states of a system of objects, entangled states are linear superpositions of the internal states of the system that cannot be separated into product states of the individual objects. Entanglement is recognized as entirely quantummechanical effect which is not only at the heart of the distinction between quantum and classical mechanics but also have played a crucial role in many discussions on fundamental issues of quantum mechanics [3][4][5]. Apart from the importance to understand the fundamentals of quantum physics, entanglement provides a fascinating avenue of research in different areas of physics, mathematics and biology.…”

Section: Introductionmentioning

confidence: 99%

Quantum entanglement and disentanglement of multi-atom systems

Ficek

2009

Front. Phys. China

View full text Add to dashboard Cite

We present a review of recent research on quantum entanglement, with special emphasis on entanglement between single atoms, processing of an encoded entanglement and its temporary evolution. Analysis based on the density matrix formalism are described. We give a simple description of the entangling procedure and explore the role of the environment in creation of entanglement and in disentanglement of atomic systems. A particular process we will focus on is spontaneous emission, usually recognized as an irreversible loss of information and entanglement encoded in the internal states of the system. We illustrate some certain circumstances where this irreversible process can in fact induce entanglement between separated systems. We also show how spontaneous emission reveals a competition between the Bell states of a two qubit system that leads to the recently discovered "sudden" features in the temporal evolution of entanglement. An another problem illustrated in details is a deterministic preparation of atoms and atomic ensembles in long-lived stationary squeezed states and entangled cluster states. We then determine how to trigger the evolution of the stable entanglement and also address the issue of a steered evolution of entanglement between desired pairs of qubits that can be achieved simply by varying the parameters of a given system.

show abstract

Speakable and Unspeakable in Quantum Mechanics

Cited by 2,080 publications

References 0 publications

Joint measurements of spin, operational locality, and uncertainty

Joint measurements of spin, operational locality, and uncertainty

Bell Locality and the Nonlocal Character of Nature

Quantum entanglement and disentanglement of multi-atom systems

Contact Info

Product

Resources

About