De Broglie wavelength - model for comparing photons and electrons

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SUMMARY

The discussion centers on the comparison of the de Broglie wavelength of photons and electrons. It establishes that for photons, the de Broglie wavelength corresponds to the distance between successive crests of oscillating electric and magnetic fields, while for electrons, it relates to the oscillating probability function. The conversation highlights the inadequacies of the Schrödinger equation for analyzing photons and suggests that Quantum Field Theory (QFT) may provide a more comprehensive understanding. The participants seek a model that effectively compares the wavelengths of both particles without switching between classical and quantum frameworks.

PREREQUISITES
  • Understanding of de Broglie wavelength concepts
  • Familiarity with electromagnetic (EM) fields and their oscillations
  • Basic knowledge of Quantum Field Theory (QFT)
  • Awareness of the Schrödinger equation and its limitations
NEXT STEPS
  • Research Quantum Field Theory (QFT) and its application to particle physics
  • Explore the Heisenberg picture in QFT for field evolution
  • Study the relationship between probability functions and wavefunctions in quantum mechanics
  • Investigate semi-classical models that unify classical and quantum descriptions of particles
USEFUL FOR

Physicists, students of quantum mechanics, and anyone interested in the fundamental properties of particles and their wave-like behavior.

HJ Farnsworth
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Hello,

I'm thinking about the wavelength of a freely propagating photon vs. a freely propagating electron.

For the photon, we have the classical picture of oscillating E and B fields perpendicular to the direction of propagation, and we call the wavelength of the photon, which can be identified as its de Broglie wavelength, as the length between successive crests of either of those fields.

For an electron, we can use the simple quantum picture of an oscillating probability function, and we can identify the de Broglie wavelength as the length between successive crests of the probability field.

As far as I know there is no transverse oscillating EM field associated with a freely propagating electron, and the Schrödinger equation is inadequate to analyze the wavefunction of a photon - so, the classical picture of the dB wavelength fails for the electron, and the quantum picture fails for the photon.

Probably something like QFT is needed to really understand what is going on, but does anyone know of a model or a conceptual picture that makes sense for a direct comparison for the wavelengths of electrons or photons that doesn't require jumping between two theories? For instance, can a freely propagating electron be modeled as an oscillating EM field in the same manner as a photon (this doesn't seem correct to me, but I'm wanting to give an idea of the kind of thig I'm looking for)? Similarly, can we picture the photon as a propagating probability oscillation (or more what I'm looking for, if so how does this then lead to the classical oscillating EM fields)? Or is there a good semi-classical model that fits both well, and reveals some interesting stuff as a result/gives a good intuition of why the concept of a dB wavelength is applicable to both photons and electrons as a result?

Thanks very much.
 
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