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QNT-16

de Broglie wavelength

λ = h / p. Matter waves for a momentum p.

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Quantade Broglie

Governing equation

λ=h/p\lambda=h/p

where

p
Momentum (keV/c)
\lambda
Wavelength (pm)

Lecture brief

Historical brief

Planck (1900), Einstein’s photoelectric law, Bohr, de Broglie, Heisenberg and Schrödinger’s 1926 equation rebuilt matter as amplitude. These sheets are the first solvable models: wells, spin, tunneling, uncertainty. This sheet (QNT-16 — de Broglie wavelength) is the form associated with de Broglie. Working symbols: pp →\rightarrow λ\lambda. Electrons in a crystal diffract like X-rays. Davisson–Germer.

Purpose

Purpose: compute λ\lambda from pp in Quantum mechanics via λ=h/p\lambda=h/p λ = h / p. Matter waves for a momentum p. Use it when a real quantum mechanics question must be answered in SI before a code check.

Live realistic example

In symbols

Live case. Given p=100.000 keV/cp = 100.000\,\mathrm{keV/c}, the governing relation λ=h/p\lambda=h/p yields λ=12.4000 pm\lambda = 12.4000\,\mathrm{pm}. A particle, a trailing wave. Move a slider: the numbers are this situation, not a canned story.

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Inputs

Outputs

  • Wavelength \lambda12.4000 pm
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QNT-16 · quantum
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Narration of this film

A particle, a trailing wave.

Electrons in a crystal diffract like X-rays. Davisson–Germer.

Reading speed

Watch on YouTube