Re: Pedagogy of QM Double Slit Experiment

On 2005-08-27, nightlight <nightlight@xxxxxxxxxxxxxx> wrote:
>> For example, Akira Tonomura, at Hitachi, has a page[1] describing
>> the electron double slit experimentin with modern equipment.
>> It even has a movie[2] of the detector monitor showing the
>> detection of individual electrons and the gradual formation
>> of an interference pattern.
>
> The Tonomura experiments do not show how is the effect quantiatively
> distingushable from a perfectly classical matter field i.e. whether a
> spread out Dirac matter field triggers a detector _independently_ of
> what other detectors did. A classical, even a macroscopic, system can
> easily replicate what you see on his video. Just consider a water in
> bucket with small holes -- the water above the holes forms a continuum
> (analog of field) while the droplets come out well spaced in time and
> space, one by one. To exclude the classical field case combined with
> quantized detection in this type of experiment one needs to show that
> the probability of a double drop p2 is smaller than p1*p1 i.e. that
> occurence of a drop on one hole makes occurence of drop on another
> remote hole significantly smaller than p1*p1 (cf.
> http://marcus.whitman.edu/~beckmk/QM/grangier/Thorn_ajp.pdf ).

You may be right that these details would have to be taken into account
to distinguish between the usual quantum wave function description and a
description in terms of a classical matter field. However, I think these
details are irrelevant for the purpose of this experiment. Which is to
merely demonstrate the existence of an interference pattern. The
existence of this pattern can experimentally distinguish between a
corpuscular (no interference) and a wave description (yes interference)
of the electron.

As to the nature of the wave description, other more detailed
experiments have to be performed. However, as you mentioned in another
thread, there currently doesn't exist an experiment that will tell the
self-field theory from quantum mechanics (when all the degrees of
freedom and interactions are taken into account, like in QED for
example). Therefore there is nothing objectionable in teaching the
conventional Schroedinger treatment of the electron.

Igor

.

Relevant Pages

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