Measure the speed of electron wave

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SUMMARY

The discussion focuses on measuring the speed of electron waves using the de Broglie wave theory, specifically the equations E=hv and P=h/λ. The proposed experimental setup involves a switch in a slit configuration that alters the diffractive pattern observed on a detection board. Key insights include the distinction between phase velocity (v=c^2/V) and group velocity, emphasizing that while phase velocity applies to individual Fourier components, group velocity represents the actual propagation speed of the wave packet. The conversation highlights the necessity of incorporating Special Relativity to fully understand the behavior of localized wave packets.

PREREQUISITES
  • Understanding of de Broglie wave theory
  • Familiarity with phase and group velocity concepts
  • Basic knowledge of Special Relativity
  • Experience with computer simulations of wave phenomena
NEXT STEPS
  • Explore the concept of wave packets in quantum mechanics
  • Investigate the implications of Special Relativity on wave behavior
  • Learn about diffractive patterns and their measurement techniques
  • Review computer simulation methods for wave phenomena
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Physicists, quantum mechanics researchers, and anyone interested in experimental physics and wave theory will benefit from this discussion.

zbl1905
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Measure the speed of electron wave
By theory of electron wave(E=hv=mcc,P=h/λ=mV),we can get the speed of electron wave
v=cc/V>c
but physicist consider it is not possible.I think it should proved by experiment.The follow experiment may gave us some new information.,Please look at picture
http://photo.163.com/openpic.php?user=zbl1905&pid=453581556&_dir=%2F18580977
There are three holes(A,B,C) in two boards(E F).,A switch is put in hole C.
electron wave transmit from left to right
1)At first ,the switch is closed.. Diffractive stripe will appear on board G,
2)At T1, ,the switch is opened.
3) At T2, diffractive stripe is changed.I don’t know what will happen.
4) speed of electron wave=L(CG)/(T2-T1).We can let L(CG) long enough to insure exact measure.
 
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This is the difference between the phase velocity and the signal or group velocity. You can do a computer simulation if you want to. The velocity you cite, v = c^2/V is the phase velocity. It is valid for each individual Fourier component, but as such, does not "propagate" anything, because a single Fourier component is present everywhere, at constant density. However, to simulate the "closure of the slit", you will have to introduce several Fourier components in your wave (to make up something that looks like a step function). Although each individual Fourier component will still rotate and "simulate" the phase velocity for each one, the movement of the "blob", or front of the step function will move at a totally different velocity: the group velocity.

Look up concepts such as "wave packet".
Or have a look at wikipedia: http://en.wikipedia.org/wiki/Phase_velocity and the links therein.

cheers,
Patrick.
 
zbl1905 said:
Measure the speed of electron wave
By theory of electron wave(E=hv=mcc,P=h/λ=mV),we can get the speed of electron wave
v=cc/V>c
but physicist consider it is not possible.I think it should proved by experiment.

The phase speed [itex]\frac{c^2}{v}[/itex] is not the physical speed of the particle. There is a simularity
between classical phase speed and group speed but that's only part of the story.

If you want to understand the nature of the de Broglie wave then it's
mandatory to look at it with Special Relativity in mind. It actually becomes
quite simple then. A localized wave packet at rest does have the same phase
everywhere. If you look at it from a different reference frame then the phase
becomes [itex]e^{ipx/\hbar}[/itex], that is, The wave packet becomes modulated with a sinusoidal
function with a wave length depending on the speed. This phase then moves
again with a speed of [itex]c^2/v[/itex].

This is however the effect of the non-simultaneity of special relativity.
I've gone through some effort to explain these effects here:
http://www.chip-architect.com/physics/deBroglie.pdf
with images from computer simulations.Regards, Hans
 
Last edited:

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