eli5 What are phonons? (this is not a typo, I do not mean “photons”)
In: 0
Systems of vibrations occurring within atoms that make up solids or liquids.
Example: I strike the end of a metal bar with a hammer. That hammer causes atoms at the stuck end to compress slightly, which, in turn, compresses the adjacent, non-compressed atoms. A compression wave (phonon) then travels along the bar, causing the opposite end to vibrate.
Think of a chunk of crystalline solid. The atoms inside this solid are very ordered, and as such, if there is any small movement or vibration of the atoms, it will propagate as waves. This vibration will have different frequencies/wavelengths and energies associated with it. In quantum mechanics, the energy of waves are discrete and a phonon is just a fancy way of describing one unit of energy of a vibration at a particular frequency/wavelength. At room temperature, you will have many of these waves or phonons in a crystalline solid due to the atoms vibrating a lot.
Latest Answers