Electron-phonon interaction in physics is the interaction of electrons with phonons (quanta of vibrations of the crystal lattice ).
The reason for the electron-phonon interaction is a change in the electric field due to lattice deformation, called the deformation potential . The presence of electron-phonon interaction leads to the appearance of attraction between electrons located near the Fermi surface .
Content
Interaction Mechanism
Visual Explain
The mechanism of electron-phonon interaction can be clearly illustrated as follows: an electron located between the ions of the crystal lattice attracts these ions, which leads to a decrease in the distance between the ions. The magnitude of the electric field of ions in the space between them increases, which attracts other nearby electrons. In this case, the first electron loses its energy, and the energy of the attracted electron increases.
Strict explanation
The attraction of electrons near the Fermi surface is the result of the emission of a virtual phonon by one electron and its absorption by another.
Effects
Acoustoelectric Effect
The transfer of momentum from phonons to electrons is the cause of the acoustoelectric effect - the appearance of direct current or EMF in a crystal under the influence of a traveling ultrasonic wave.
Superconductivity
The attraction of electrons through electron-phonon interaction is the reason for the formation of Cooper pairs of electrons, which play an important role in superconductivity . In this case, unlike electrons, which are fermions , Cooper pairs are quasibosons capable of forming a Bose condensate .
See also
- Phonon
Sources
- E. M. Lifshits, L.P. Pitaevsky. Theoretical Physics: Statistical Physics, Part 2, Volume 9. M .: Nauka, 1978. - 449 pp.