APS March Meeting 2013
Volume 58, Number 1
Monday–Friday, March 18–22, 2013;
Baltimore, Maryland
Session W3: Invited Session: Quantum Foundations
2:30 PM–5:30 PM,
Thursday, March 21, 2013
Room: Ballroom III
Sponsoring
Unit:
GQI
Chair: Terry Rudolph, Imperial College London
Abstract ID: BAPS.2013.MAR.W3.2
Abstract: W3.00002 : Quantum correlations in Newtonian space and time: arbitrarily fast communication or nonlocality
3:06 PM–3:42 PM
Preview Abstract
Abstract
Author:
Nicolas Gisin
(University of Geneva)
Experimental violations of Bell inequalities using space-like separated
measurements precludes the explanation of quantum correlations through
causal influences propagating at subluminal speed. Yet, ``everything looks
as if the two parties somehow communicate behind the scene.'' We investigate
the assumption that they do so at a speed faster than light, though finite.
Such an assumption doesn't respect the spirit of Einstein relativity.
However, it is not crystal clear that such ``communication behind the
scene'' would contradict relativity. Indeed, one could imagine that this
communication remains for ever hidden to humans, i.e. that it could not be
controlled by humans, only Nature exploits it to produce correlations that
can't be explained by usual common causes. To define faster than light
hidden communication requires a universal privileged reference frame in
which this faster than light speed is defined. Again, such a universal
privileged frame is not in the spirit of relativity, but it is also clearly
not in contradiction: for example the reference frame in which the cosmic
microwave background radiation is isotropic defines such a privileged frame.
Hence, a priori, a hidden communication explanation is not more surprising
than nonlocality.
We prove that for \textit{any} finite speed, such models predict correlations that can
be exploited for faster-than-light communication. This superluminal
communication doesn't require access to any hidden physical quantities, but
only the manipulation of measurement devices at the level of our present-day
description of quantum experiments. Consequently, all possible explanations
of quantum correlations that satisfy the principle of continuity, which
states that everything propagates gradually and continuously through space
and time, or in other words, all combination of local common causes and
direct causes that reproduce quantum correlations, lead to faster than light
communication. Accordingly, either there is superluminal communication or
the conclusion that Nature is nonlocal (i.e. discontinuous) is unavoidable
[Nature Physics DOI: 10.1038/NPHYS2460 (2012); arXiv:1210.7308].
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2013.MAR.W3.2