DavissonGermer

The Davisson–Germer experiment is a foundational demonstration of wave-particle duality for electrons. Conducted by Clinton Davisson and Lester Germer at Bell Telephone Laboratories in 1927, the work provided direct evidence that electrons exhibit wave-like properties, in line with Louis de Broglie’s hypothesis. The results helped establish the wave nature of matter and contributed to the acceptance of quantum mechanics.

In the experiment, a beam of electrons was produced by a heated filament and accelerated toward a single-crystal nickel target. Scattered electrons were collected on a detector, and the intensity was measured as a function of the angle of scattering. The observed diffraction pattern showed distinct maxima, consistent with Bragg diffraction, and matched the de Broglie wavelength λ = h/p for the electrons. For electrons with kinetic energies around 54 eV, the wavelength is about 0.167 nanometers.

The findings demonstrated that electrons can diffract as waves when interacting with a crystalline lattice, confirming that matter can exhibit interference. The results aligned with Bragg’s law for crystal lattices and were interpreted within the framework of quantum mechanics as evidence of matter waves.

The work had a lasting impact on physics and the broader understanding of quantum phenomena. In 1937, Clinton Davisson and George Paget Thomson were awarded the Nobel Prize in Physics for the experimental demonstration of electron diffraction; Lester Germer did not receive the prize. The Davisson–Germer experiment remains a classic milestone illustrating the wave-particle duality of matter.