Search results
Results from the WOW.Com Content Network
The de Broglie relation, [10] [11] [12] also known as de Broglie's momentum–wavelength relation, [4] generalizes the Planck relation to matter waves. Louis de Broglie argued that if particles had a wave nature, the relation E = hν would also apply to them, and postulated that particles would have a wavelength equal to λ = h / p .
The de Broglie wavelength is the wavelength, λ, associated with a particle with momentum p through the Planck constant, h: =. Wave-like behavior of matter has been experimentally demonstrated, first for electrons in 1927 and for other elementary particles , neutral atoms and molecules in the years since.
For quantum mechanical waves, the wavenumber multiplied by the reduced Planck constant is the canonical momentum. Wavenumber can be used to specify quantities other than spatial frequency. For example, in optical spectroscopy, it is often used as a unit of temporal frequency assuming a certain speed of light.
A dispersion relation relates the wavelength or wavenumber of a wave to its frequency. Given the dispersion relation, one can calculate the frequency-dependent phase velocity and group velocity of each sinusoidal component of a wave in the medium, as a function of frequency
The Planck constant, or Planck's constant, denoted by , [1] is a fundamental physical constant [1] of foundational importance in quantum mechanics: a photon's energy is equal to its frequency multiplied by the Planck constant, and the wavelength of a matter wave equals the Planck constant divided by the associated particle momentum.
The Compton wavelength for this particle is the wavelength of a photon of the same energy. For photons of frequency f , energy is given by E = h f = h c λ = m c 2 , {\displaystyle E=hf={\frac {hc}{\lambda }}=mc^{2},} which yields the Compton wavelength formula if solved for λ .
For photons, this is the relation, discovered in 19th century classical electromagnetism, between radiant momentum (causing radiation pressure) and radiant energy. If the body's speed v is much less than c , then ( 1 ) reduces to E = 1 / 2 m 0 v 2 + m 0 c 2 ; that is, the body's total energy is simply its classical kinetic energy ...
The momentum transfer plays an important role in the evaluation of neutron, X-ray, and electron diffraction for the investigation of condensed matter. Laue-Bragg diffraction occurs on the atomic crystal lattice, conserves the wave energy and thus is called elastic scattering, where the wave numbers final and incident particles, and , respectively, are equal and just the direction changes by a ...