De Broglie wavelength

(quantum mechanics) The wavelength of the wave associated with a particle as given by the de Broglie relation.

The wavelength γ = h/p associated with a beam of particles (or with a single particle) of momentum p; h = 6.626 × 10³⁴ joule-second is Planck's constant. The same formula gives the momentum of an individual photon associated with a light wave of wavelength γ. This formula, along with the profound proposition that all matter has wavelike properties, was first put forth by Louis de Broglie in 1924, and is fundamental to the modern theory of matter and its interaction with electromagnetic radiation. See also Quantum mechanics.