Locality, separation and entanglement – 1930s style. We’ll
explore the background to the 1935 paper by Einstein,
Podolsky and Rosen, how it was composed, the actual argument
of the paper, the principles used, and how the paper was
received by Schroedinger, and others.We’ll also look at
Bohr’s response: the extent to which Bohr connects with what
Einstein was after in EPR and the extent to EPR marks a
shift in Bohr’s thinking about the quantum theory.
[C1.002] Interpretations of Entanglement
Martin Jones (Philosophy Department, Oberlin College)
The peculiar statistical correlations between spatially
separated systems which arise in quantum mechanics, and
which the Einstein-Podolsky-Rosen paper of 1935 thrust into
the limelight, have been the focus of much interpretive
speculation and disagreement in the years since then.
Amongst the questions raised along the way have been
questions about the possibility of superluminal causation,
the limits of quantum mechanics and its relation to
relativity theory, the nature of and need for causal
explanation, realism, determinism, and the presence of
holism in quantum mechanics. This talk will provide an
historically structured overview of these debates –
including discussion of the Bohm theory, the many worlds
interpretation, and more recent developments – and will
suggest a way of dividing many of the interpretations of
entanglement into clusters of like-minded views.
[C1.003] Experimental tests of Bell's inequalities: the Orsay's 1982 experiments
Alain Aspect (Institut d'Optique, ORSAY, France)
After the pioneering work of Clauser and Freedman in the early 70's, and Fry in the mid 70's, we have developped in Orsay a very efficient source of pairs of correlated photons to investigate - by testing Bell's inequalities - entanglement in the Einstein Podolsky Rosen situation. This source allowed us to carry out several experiments of 3rd generation, with new schemes close to the ideal Gedanken Experiment scheme.
In this presentation, I will first recall what is Bell's theorem, and why
it is such an important milestone in the understanding of Quantum
Mechanics. I will then present the new schemes that we have been able to
implement in 1982, which were very close to the ideal scheme discussed by
John Bell. I will finally rapidly review the recent experiments which take
advantage of the progress of quantum optics in the last decades.
[C1.004] Quantum Entanglement and Information
Anton Zeilinger (Institut fuer Experimentalphysik, University of Vienna, Austria)
The development of quantum entanglement presents a very
interesting and typical case how fundamental reasearch leads
to new technologically interesting concepts. Initially it
was introduced by Einstein and Schroedinger because of its
philosophical interest. This, together with Bell's theorem,
led to experiments beginning in the early 1970-s which also
were only motivated by their importance for the foundations
of physics. Most remarkably, in recent years people
discovered that quantum entanglement can be useful in
completely novel ways of transmitting and processing of
information with no analog in classical physics. Here the
most developed areas are quantum communication, quantum
cryptography, quantum teleportation and quantum computation.
In the talk I will present the basics of these applications
of entanglement and I will discuss some existing
experimental realisations. Finally I will argue that, while
it is impossible to foresee where the present development
will lead us, it is very likely that in the end a novel kind
of information technology will emerge.
[C1.005] Commentary
Guido Bacciagaluppi (University of California)
This abstract not available.