269 research outputs found
Event-by-event simulation of the Hanbury Brown-Twiss experiment with coherent light
We present a computer simulation model for the Hanbury Brown-Twiss experiment
that is entirely particle-based and reproduces the results of wave theory. The
model is solely based on experimental facts, satisfies Einstein's criterion of
local causality and does not require knowledge of the solution of a wave
equation. The simulation model is fully consistent with earlier work and
provides another demonstration that it is possible to give a particle-only
description of wave phenomena, rendering the concept of wave-particle duality
superfluous.Comment: Submitted to Commmun. Comput. Phy
Event-by-event simulation of experiments to create entanglement and violate Bell inequalities
We discuss a discrete-event, particle-based simulation approach which
reproduces the statistical distributions of Maxwell's theory and quantum theory
by generating detection events one-by-one. This event-based approach gives a
unified cause-and-effect description of quantum optics experiments such as
single-photon Mach-Zehnder interferometer, Wheeler's delayed choice, quantum
eraser, double-slit, Einstein-Podolsky-Rosen-Bohm and Hanbury Brown-Twiss
experiments, and various neutron interferometry experiments at a level of
detail which is not covered by conventional quantum theoretical descriptions.
We illustrate the approach by application to single-photon
Einstein-Podolsky-Rosen-Bohm experiments and single-neutron interferometry
experiments that violate a Bell inequality.Comment: arXiv admin note: substantial text overlap with arXiv:1208.236
Irrelevance of Bell's Theorem for experiments involving correlations in space and time: a specific loophole-free computer-example
John Bell is generally credited to have accomplished the remarkable "proof"
that any theory of physics, which is both Einstein-local and "realistic"
(counterfactually definite), results in a strong upper bound to the
correlations that are measured in space and time. He thus predicts that
Einstein-Podolsky-Rosen experiments cannot violate Bell- type inequalities. We
present a counterexample to this claim, based on discrete-event computer
simulations. Our model-results fully agree with the predictions of quantum
theory for Einstein-Podolsky-Rosen-Bohm experiments and are free of the
detection- or a coincidence-loophole
Data analysis of Einstein-Podolsky-Rosen-Bohm laboratory experiments
Data sets produced by three different Einstein-Podolsky-Rosen-Bohm (EPRB)
experiments are tested against the hypothesis that the statistics of this data
is described by quantum theory. Although these experiments generate data that
violate Bell inequalities for suitable choices of the time-coincidence window,
the analysis shows that it is highly unlikely that these data sets are
compatible with the quantum theoretical description of the EPRB experiment,
suggesting that the popular statements that EPRB experiments agree with quantum
theory lack a solid scientific basis and that more precise experiments are
called for.Comment: arXiv admin note: substantial text overlap with arXiv:1112.262
Is Einsteinian no-signalling violated in Bell Tests?
Relativistic invariance is a physical law verified in several domains of
physics. The impossibility of faster than light influences is not questioned by
quantum theory. In quantum electrodynamics, in quantum field theory and in the
standard model relativistic invariance is incorporated by construction. Quantum
mechanics predicts strong long range correlations between outcomes of spin
projection measurements performed in distant laboratories. In spite of these
strong correlations marginal probability distributions should not depend on
what was measured in the other laboratory what is called shortly:
non-signalling. In several experiments, performed to test various Bell-type
inequalities, some unexplained dependence of empirical marginal probability
distributions on distant settings was observed . In this paper we demonstrate
how a particular identification and selection procedure of paired distant
outcomes is the most probable cause for this apparent violation of
no-signalling principle. Thus this unexpected setting dependence does not prove
the existence of superluminal influences and Einsteinian no-signalling
principle has to be tested differently in dedicated experiments. We propose a
detailed protocol telling how such experiments should be designed in order to
be conclusive. We also explain how magical quantum correlations may be
explained in a locally causal way.Comment: 26 pages,2 figures, 23 equations, 107 references. It is a revised
version in which some misprints were corrected and 4 references added. The
paper was accepted for publication and will be published soo
Closing the door on quantum nonlocality
Bell-type inequalities are proven using oversimplified probabilistic models and/or
counterfactual definiteness (CFD). If setting-dependent variables describing measuring instruments
are correctly introduced, none of these inequalities may be proven. In spite of this, a belief in a
mysterious quantum nonlocality is not fading. Computer simulations of Bell tests allow people to
study the different ways in which the experimental data might have been created. They also allow for
the generation of various counterfactual experiments’ outcomes, such as repeated or simultaneous
measurements performed in different settings on the same “photon-pair”, and so forth. They allow
for the reinforcing or relaxing of CFD compliance and/or for studying the impact of various “photon
identification procedures”, mimicking those used in real experiments. Data samples consistent
with quantum predictions may be generated by using a specific setting-dependent identification
procedure. It reflects the active role of instruments during the measurement process. Each of the
setting-dependent data samples are consistent with specific setting-dependent probabilistic models
which may not be deduced using non-contextual local realistic or stochastic hidden variables. In this
paper, we will be discussing the results of these simulations. Since the data samples are generated in
a locally causal way, these simulations provide additional strong arguments for closing the door on
quantum nonlocality
Event-based simulation of quantum physics experiments
We review an event-based simulation approach which reproduces the statistical
distributions of wave theory not by requiring the knowledge of the solution of
the wave equation of the whole system but by generating detection events
one-by-one according to an unknown distribution. We illustrate its
applicability to various single photon and single neutron interferometry
experiments and to two Bell test experiments, a single-photon
Einstein-Podolsky-Rosen experiment employing post-selection for photon pair
identification and a single-neutron Bell test interferometry experiment with
nearly detection efficiency.Comment: Lectures notes of the Advanced School on Quantum Foundations and Open
Quantum Systems, Jo\~ao Pessoa, Brazil, July 2012, edited by T. M.
Nieuwenhuizen et al, World Scientific, to appea
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