Science Pills: What is a phonon?

You may be familiar with the word "photon", the particle that carries all forms of electromagnetic radiation including gamma rays, x-rays, ultraviolet light or visible light, but you may not be familiar with a particle with a similar name: phonon.

This word is derived from Greek and means "sound". In quantum mechanics it's defined as a basic vibrational movement in which a network of atoms or molecules oscillates uniformly at a single frequency.

If we take for example the atoms of a crystal we would see that they aren't constituted in a static way but that, according to the temperature, the atoms of this crystal would have some small vibrations that are essentially the energy that this material has in itself.

The vibrations of these atoms in the vertices of the different geometric figures that make up the study material don't vibrate with a certain amplitude but are perfectly quantified and each of these vibrations with what is called phonon.

The concept of phonon was introduced in 1932 by the soviet physicist Igor Tamm and his study is of great importance because it is related to the thermal and electrical conductivity of each material and its heat capacity that relates the energy that we apply to a material and how much it increases their temperature.