What are the equation(s) that determine free electron wave amplitude?

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The discussion centers on the distinction between the wave function and the physical free electron wave. It clarifies that a plane-wave approximation, while commonly referenced, is not a proper wave function due to its non-normalizability, which results in an undefined amplitude. Instead, a wave packet, represented by the equation ψ(x,t) = ∫[−∞, +∞] a(k)e^(ikx−ω_kt)dk, provides a valid description of electron waves, allowing for meaningful amplitude calculations through normalization. The normalization condition is essential for obtaining true amplitudes from the wave packet.

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jaketodd
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I'm not talking about the wavefunction but instead, the physical free electron wave.

Thanks!
 
Last edited:
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If you don't mean the wave function, what do you mean by 'physical free electron wave'?

If you mean the 'electron waves' you were talking about in your previous thread:
https://www.physicsforums.com/showthread.php?t=324515

Then, all the answers there are talking about the wave function. (specifically, a plane-wave approximation to the wave function) But a plane-wave is not actually a proper wave function. It's not square-integrable and so it can't be normalized. That also means that it doesn't have a meaningful amplitude (in absolute terms).

If you want a real wave function (that's normalizable), you need a wave packet:
[tex]\psi(x,t) = \int^{+\infty}_{-\infty}a(k)e^{ikx-\omega_kt}dk[/tex]
Where a(k) is some function describing the overall shape of the packet.

In which case you'll get the true amplitudes from applying the nomalization condition.
 
I used this page to convert the latex to an image i can actually see: http://www.equationsheet.com/textoimage.php

and I don't know what all the variables and/or constants are, please fill me in if you'd be so kind
 

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